Operating Manual Optical Receiver ORS 600 / ORS 800

Operating Manual Optical Receiver ORS 600 / ORS 800 OPT. IN RF LEVEL LASER KLASSE 1 REMOTE UNSICHTBARE LASERSTRAHLUNG NICHT IN DEN STRAHL BLICKEN AUCH NICHT MIT OPTISCHEN INSTRUMENTEN OPT RF 20 db ORS 045 806-001-02-197

Overview Note The information in this manual is subject to alteration at any time. HIRSCHMANN ACCEPTS NO LIABILITY OF ANY KIND (SUCH AS FOR MATERIAL DEFECTS, STATUTORY GUARANTEE, MARKETABILITY, VIOLATION OF EXISTING PATENT RIGHTS) EXCEPT AS ALLOWED FOR UNDER THE TERMS OF THE GUARANTEE DETAILED IN THIS MANUAL. This manual includes information protected by copyright. All rights are reserved. No part of this manual may be photocopied, duplicated in any way whatsoever or translated into another language without the prior written consent of HIRSCHMANN. IMPORTANT: Read the Explanation of Warning and Information Symbols and the Warnings and Safety Instructions carefully before commissioning. Always keep this manual close at hand. 0-2 Operating Manual, Optical Receiver

Overview Contents Contents Overview Notes for the User....................... 0-4 Layout of the Operating Manual......................... 0-4 Explanation of Warning and Information Symbols.................. 0-4 Warnings and Safety Instructions Required by IEC 825 (11/1993)............ 0-5 Operating Instructions Description of Function..................... 1-1 Interfaces.......................... 1-2 Front Panel.................................. 1-2 Rear Panel Function Connector Assignment.................... 1-2 Commissioning....................... 1-3 General Information.............................. 1-3 Commissioning the BGS / BGA Module Rack................. 1-3 Basic Requirements.............................. 1-3 Adjusting to the Optical Input Power....................... 1-4 Setting the HF Output Level........................... 1-5 Connecting the Fibre Optic Cable......................... 1-6 Operating Statuses...................... 1-7 Fault Diagnosis....................... 1-7 Modifications......................... 1-8 Servicing/Maintenance Important Notes........................ 2-1 Standard Settings....................... 2-1 Factory Settings................................ 2-1 Checking Function....................... 2-1 Storage and Handling..................... 2-1 Replacement Parts and Accessories................ 2-2 Manufacturer s Agents/Customer Service.............. 2-2 Data Sheets......................... 2-2 Operating Manual, Optical Receiver 0-3

Overview Notes for the User Notes for the User Layout of the Operating Manual Chapter 1 Contains the description of function, basic requirements and commissioning instructions. Chapter 2 Contains the information necessary for servicing and maintenance. Explanation of Warning and Information Symbols WARNING: Indicates that failure to observe safety precautions identified by this symbol could result in personal injury and/or damage to machinery and equipment. CAUTION: Indicates that failure to observe safety precautions identified by this symbol could result in damage to property. NOTE: Notes and useful tips for practical use of the equipment. 0-4 Operating Manual, Optical Receiver

Overview Notes for the User Warnings and Safety instructions Required by IEC 825 (11/1993) Warning! Before commissioning, carefully read the operating instructions. The unit uses an invisible laser beam. Do not expose yourself to the laser beam. The laser is rated as a Class 1 and Class 3A laser (depending on model of the OTS optical transmitter). Operation of the unit is only permissible if the following requirements are satisfied: 1. The unit must be operated in a BGS /BGA 19 module rack in the slot intended for it. 2. The unit may only be operated in conjunction with an OTRS 60 return channel transmitter. 3. The unit may only be operated with sealed fibre optic transmission cable links from which it is not possible for the laser beam to escape. DFB Laser (in OTS optical transmitter) Wave lenght Laser output power WARNING Safety Instructions 1290 nm to 1330 nm max. 6-20 mw, dispending on model Caution - if operating or adjusting equipment other than that specified in this manual is used or other methods or procedures applied, dangerous exposure to irradiation may result. The ends of pigtails, disconnected connectors and breaks in the fibre optic cable for AM-CATV transmission constitute potential points of escape for the laser beam. Switch off the optical transmitter before disconnecting connectors or working on pigtails or the fibre optic cable. Operating Manual, Optical Receiver 0-5

NVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS CLASS 3A LASER Overview Notes for the User OPT. IN RF LEVEL Normally CLASS 1 LASER CLASS 1 LASER In event of fault CLASS 3A LASER CLASS 1 LASER REMOTE OPT RF 20 db ORS Notes: The laser beam enters the unit through the optical connector below the cover. The fiber optic cable connected at this point is a potential point of escape for the laser beam. Do not operate the unit until all fibre optic cable links between the transmitter and the receivers are fully connected up! Normally CLASS 1 LASER CLASS 1 LASER CLASS 1 LASER In event of fault CLASS 3A LASER INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS CLASS 3A LASER Fig. 1: Position of warning labels on front and side panels of the optical receiver 0-6 Operating Manual, Optical Receiver

Operating Instructions Description of Function Description of Function The ORS optical receiver is fitted with a low-noise PIN photo diode and receives an intensity modulated signal sent via a fibre optic cable. It converts that signal into an HF signal for feeding into cable networks. The optical receiver is designed as a 19 plug-in module. It is intended for use in conjunction with a matching OTRS 60 return channel transmitter in a BG module rack. The rear-panel board of the module rack forms the connection between the optical receivers and return channel transmitters. The optical receiver is slotted into the module rack from the front between guide rails. At the same time the electrical connections with the rear panel board are established by means of blade connectors. All the optical receiver connections are located on its rear panel. A testing output for checking the output signal and an output for monitoring the optical input power are located on the front panel. An additional HF input (RF IN) enables auxiliary signals to be fed in that are connected through to the module output in the event of a fault (HF signal not present, power supply failure). The unit can also be switched over to telecontrol by means of the PC monitoring system. This disables automatic switch-over. The unit has the facility for adjusting the receiver to different transmission line optical attenuation levels setting the desired HF output level selecting the operating mode of the integral HF selector (standard setting auto, normally changed only for servicing/maintenance purpos!) Information about the module status is sent via the system bus to the PC monitoring system. 20 db 75 MP opt. AM CATV FC/APC 0 15 db 0 7 db 75 50 50 RF OUT 75 dbpw (92 dbµv) ± 3 db OPT. IN Optical input power Output level 50 + 12 V + 24 V 12 V U B RF level approx. 80 450 MHz Auxiliary signal RF IN Module bus System bus Shut Down Analysis and monitoring Red LED (fault) Green LED (OPT. IN) Green LED (RF LEVEL) Yellow LED (REMOTE) OPT Fig. 2: Block diagram of ORS optical receiver Operating Manual, Optical Receiver 1-1

Operating Instructions Interfaces Interfaces Front Panel CLASS 1 LASER OPT. IN RF LEVEL REMOTE Lights up (red) in the event of a fault, see PC Monitoring System under FAULT. Lights up if the level of the optical input signal is sufficient. Lights up if the internal HF signal is present. Lights up if telecontrol is active. INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS Behind the cover is the laser inlet; the fibre optic cable is connected by means of a coupling. OPT Monitoring output for checking the optical input power. RF 20 db Testing socket (75 Ω, -20 db) for checking the output signal. ORS Fig.3: Front view of optical receiver Rear Panel Function Connector Assignment The function connectors on the rear-panel board of the module rack are connected to control lines, message lines, etc. The pin assignment of the connectors on the BG module rack is indicated in the relevant data sheets. 1-2 Operating Manual, Optical Receiver

Operating Instructions Commissioning Commissioning General Information Commissioning the BGS / BGA Module Rack Refer to the operating manual for the BGS /BGA module rack. Basic Requirements CAUTION: - The optical receiver and module rack may only be commissioned by properly trained persons. - If there is condensation on the units when they are unpacked, allow them to acclimatise for at least one hour before commissioning. WARNING: - There must be no breaks in the fibre optic cable at any point between the optical transmitter and the optical receiver; the laser beam must not be allowed to escape from the system at any point. The unit may only be commissioned in conjunction with the OTRS 60 return channel transmitter. 1. Do not commission the optical receiver until the fibre optic cable is connected to the optical input the jumpers for optical input power and output level have been set the operating mode for the output signal has been selected (see Fig. 7, page 2-1) and you have read the operating manual for the BGS /BGA module rack. 2. The optical input power and the output level must be set with the unit open. The adjusting controls are located on the PCB below the right-hand side cover when viewed from the front. 3. The optical receiver is commissioned by slotting it into the module rack. This can be done while the module rack is in operation. Operating Manual, Optical Receiver 1-3

Operating Instructions Adjusting to the Optical Input Power Adjusting to the Optical Input Power The attenuation required depends on the optical input power (max. 2 mw permissible). The ORS optical receiver is supplied with the attenuation set to 11 db. The unit is adjusted to the optical input power as follows: Commission the ORS with the attenuation at the factory setting. Measure the level of the HF signal, e.g. 91 dbµv, at the testing socket (note that the level at the testing socket is reduced by 20 db). Determine the difference between the level measured and the maximum output level of 95 dbµv, e.g. 95 dbµv 91 dbµv = 4 dbµv. Alter the factory attenuation setting by that amount - in this example by 4 db from 11 db to 7 db. The position of the jumpers for setting the attenuation is shown in Fig.4. There are 5 pairs of jumpers in all which must always be set in pairs. There are a total of 16 different attenuation settings possible from 0 db to 15 db in 1-dB increments. The 0.5-dB jumpers are for fine adjustment of the output level. 0 db 8 db 0 db 0 db 0 db 4 db 2 db 1 db 0 db 0,5 db In this example, the jumpers marked 1 db, 2 db and 4 db must be set. Fig. 4: Example showing position of jumpers for attenuation setting of 7 db 1-4 Operating Manual, Optical Receiver

Operating Instructions Setting the HF Output Level Setting the HF Output Level The jumpers shown in Fig. 5 are used to adjust the HF level at the optical receiver output to the prevailing conditions. The maximum level of 95 dbµv ( 78 dbpw) is obtained at the 0 db setting and can be reduced by up to 7 db. If fine adjustment is required, it can be achieved by means of the 0.5-dB jumpers shown in Fig. 4. The position of the jumpers for setting the HF output level is shown in Fig. 4. There are 3 pairs of jumpers in all which must always be altered in pairs. There are a total of 8 different possible attenuation settings from -7 db to 0 db in 1-dB increments. 0 db 4 db 2 db 0 db 0 db 1 db In this example, the jumpers marked 1 db must be set. Fig. 5: Example showing position of jumpers for HF output level of 94 dbµv ( 77 dbpw) Operating Manual, Optical Receiver 1-5

Operating Instructions Connecting the Fibre Optic Cable Connecting the Fibre Optic Cable To connect the fibre optic cable, first remove the cover by removing the screws. Then unscrew the protective cap (see Fig. 6). Insert the fibre optic AM-CATV cable connector in the socket and tighten the sleeve nut. Replace the cover. Screw OPT. IN CLASS 1 LASER RF LEVEL REMOTE Cover INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS Protective cap OPT RF 20 db ORS Fig. 6: Removing the protective cap 1-6 Operating Manual, Optical Receiver

Operating Instructions Operating Statuses Operating Statuses Signal Yellow REMOTE LED lights up Green OPT. IN LED lights up Green RF LEVEL LED lights up Status Telecontrol active, operating mode selected on hardware (HF relay setting) inactive Optical input power within permissible range HF signal at output correct Fault Diagnosis Symptom Possible Cause Remedy ➀ Red LED lights up No power supply Check power supply (24 V, 12 V and -12 V) and fuses, replace fuse(s) if necessary ➁ Red LED lights up 3 Red LED lights up Optical input power too low due to fault in optical link as follows: - Transmitter laser switched off - Push transmitter fully home in module rack - Fibre optic cable not correctly - Check fibre optic cable connected connector for proper contact, there must be no dirt on contact surfaces of the connector - Fibre optic cables for forward and return - Check connections and channel link reversed correct if necessary - Fibre optic cable damaged - Check fibre optic cable for breaks and splice if necessary No HF signal as follows: - No signals or too few signals in frequency - Ensure signals from range 80 450 MHz transmitter station are within the specified range Red LED + green No power supply and/or HF signal See ➀ and 3 OPT. IN LED light up Red LED + green - No power supply - See ➀ RF LEVEL LED - Optical input power outside permissible - See ➁ permanently lit range but HF signals present - ORS defective - Send unit to service centre for repair Operating Manual, Optical Receiver 1-7

Operating Instructions Modifications Modifications 1-8 Operating Manual, Optical Receiver

Servicing/Maintenance Important Notes CAUTION: Maintenance work may only be carried out by properly trained persons. Standard Settings Factory Settings Factory setting for jumpers: - Output level: 0 db - Optical input power: 11 db - Auto operating mode. By changing this jumper setting to internal or external, the output can be switched to the internal or external signal (auxiliary signal) regardless of the HF level. These operating modes are intended for servicing and testing purposes only. Fig. 7: Position of jumper for selecting operating mode ext. int. auto Checking Function The PC monitoring program should be used for checking the function of the unit. Storage and Handling Store the unit in its original packing at a temperature between -20 C and +70 C. The unit should not be stored in places where the air humidity levels are high or subject to large fluctuations. Operating Manual, Optical Receiver 2-1

Servicing/Maintenance Replacement Parts and Accessories Description Model Hirschmann Order No. Optical receiver ORS 600 960 736-001 Optical receiver ORS 800 960 810-001 Data processor DP 501 976 711-001 Front panel cover plate 7 TE 879 222-007 Front panel cover plate 14 TE 879 222-014 Ribbon cable 1) 5-core 778 466-005 Ribbon cable 1) 14-core 778 466-014 Manufacturer s Agents/Customer Service Germany Richard Hirschmann GmbH & Co Tel. 49-7127-14 1301 Service-Center FAX 49-7127-14 1300 Stuttgarter Str. 43 D-72654 NECKARTENZLINGEN Austria Richard Hirschmann Ges.m.b.H. Tel. 43-5522-307 0 Oberer Paspelsweg 6-8 FAX 43-5522-307 555 A-6830 RANKWEIL-BREDERIS tlx 47 52239 hirran a Netherlands Richard Hirschmann Tel. 31-2940-625 55 Electronica Nederland B.V. FAX 31-2940-806 39 Postbus 92 tlx 44 18730 rhen nl NL-1380 AB WEESP Norway Richard Hirschmann Norge A / S Tel. 47-2-50 70 10 Aslakveien 20 - Røa FAX 47-2-52 37 40 N-0701 OSLO 7 Spain Hirschmann España S.A. Tel. 34-1-75 40 208 Mr. Granados FAX 34-1-75 45 177 Calle Albalá 7 tlx 44 423 hire e E-28037 MADRID Hungary Hirschmann-BHG Tel. 36-1-149 7575 Hiradástechnikai Kft. FAX 36-1-129 8453 Rokolya u. 1-13 H-1131 BUDAPEST Data Sheets Optical receiver... Data sheet pages 1/6 6/6 1) for connecting two BGS 03 module racks 2-2 Operating Manual, Optical Receiver

Data Sheet Description of Unit The ORS optical receiver receives an intensity modulated optical signal from a fibre optic cable and converts it into electrical signals in the frequency range 47 MHz - 606 MHz (ORS 600) or 47 MHz - 860 MHz (ORS 800). An additional input allows auxiliary signals to be fed in which are automatically connected through to the module output in the event of a fault (HF signal not present, power supply failure). The switch-over can also be effected via the PC monitoring system. In this case, automatic switch-over is overridden. The unit is designed as a 19 plug-in module. On the front panel are the optical input, the RF 20 db testing socket for checking the output signal, the monitoring output OPT for checking the optical input power and four LEDs for signalling the operating statuses or indicating faults on the module. The power supply and the system bus are connected via the multi-point blade connector on the rear panel of the unit. The connectors for the HF signals are integrated in the multi-point connector. A low-noise PIN photodiode converts the optical input signal into an electrical HF signal. The HF output signal can be adjusted in 1-dB increments by altering the position of jumpers. A monitoring circuit registers the optical power received and generates a shut-down signal from it which is used to reduce the laser power transmitted in the event of loss of optical power (e.g. due to broken fibre) in order to comply with the safety requirements of EN 60825 (radiation safety of laser equipment). Information about the module status is sent via the system bus to the PC monitoring system. General Data Dimensions Weight Connections Rear panel : 19" plug-in module, 4 height units, 14 spacing units : 3.1 kg : Multi-point blade connector with integrated HF connectors (50 Ω, 1.0 / 2.3) DIN 41612 M Front panel RF testing output : 75 Ω (1.6 / 5.6) Optical connection : FC-APC connector or E2000 connector Rated temperature range : + 5 + 45 C Working temperature range : 0 + 50 C Storage temperature range : 20 + 70 C Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-1/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen

Data Sheet Technical Data Power supply voltage/current Frequency range ORS 600 ORS 800 : + 24 V ± 1.2 V / = 0.75 A : + 12 V ± 0.6 V / = 0.3 A : 12 V ± 0.6 V / = 0.05 A : 47 MHz - 606 MHz : 47 MHz - 860 MHz Output level : 75 dbpw ± 3 dbpw 1) Output impedance Input impedance, auxiliary signal Return loss Decoupling attenuation of testing socket relative to output signal ORS 600 ORS 800 Isolation between output and auxiliary signal input Throughput attenuation between output and auxiliary signal input : 50 Ω : 50 Ω : = 20 db at 47 MHz ( 1 db/oct.) : 20 db ± 0.5 db : 20 db ± 1.0 db : = 60 db : = 1.5 db Wavelength : 1280 nm - 1600 nm Optical input power max. : 2.0 mw min. : Refer to OptiCaT 600/OptiCaT 800 system specifications Monitor output OPT : 2 V/ mw Signalling Normal operation Opt. input power : Green LED HF level : Green LED Telecontrol : Yellow LED Fault (module fault) : Red LED Module monitoring : PC, telecontrol (see Remote Monitoring) Messages to PC monitoring system P OPT (optical power received in mw) Optical alarm Telecontrol active HF level (qualitative) Fault 1) for optical input power P opt = 2,0 dbm, for P opt < 2.0 dbm falling at 2 db/dbm Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-2/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen

Data Sheet Description Order No. ORS 600 with FC-APC connection 960 736-001 ORS 600 with E2000 connection 960 736-201 ORS 800 with FC-APC connection 960 810-001 ORS 800 with E2000 connection 960 810-201 Block Diagram 20 db 75 MP opt. AM CATV FC/APC 0 15 db 0 7 db 75 50 50 RF OUT 75 dbpw (92 dbµv) ± 3 db OPT. IN Optical input power Output level 50 + 12 V + 24 V 12 V U B RF level approx. 80 450 MHz Auxiliary signal RF IN Module bus System bus Shut Down Analysis and monitoring Red LED (fault) Green LED (OPT. IN) Green LED (RF LEVEL) Yellow LED (REMOTE) OPT Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-3/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen

INVISIBLE LASER BEAM DO NOT LOOK DIRECTLY INTO BEAM EVEN WITH OPTICAL INSTRUMENTS Data Sheet Interfaces Front Panel CLASS 1 LASER OPT. IN RF LEVEL REMOTE Lights up (red) in the event of a fault, see PC Monitoring System under FAULT. Lights up if the level of the optical input signal is sufficient. Lights up if the internal HF signal is present. Lights up if telecontrol is active. Behind the cover is the laser inlet; the fibre optic cable is connected by means of a couplin OPT Monitoring output for checking the optical input power. RF 20 db Testing socket (75 Ω, -20 db) for checking the output signal. ORS Rear Panel RF output (RF OUT), 50 Ω Multi-point connector J 1 Auxiliary signal input (RF IN), 50 Ω Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-4/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen

Data Sheet Multi-point connector J 1 Description Remarks Pin + 12 V Positive power supply A 11 / B 11 / C 11 + 24 V Positive power supply B 12 / C 12 12 V Negative power supply B 14 0 V Earth A 10 / B 10 / C 10 opt. Alarm Shut-down trigger (to return channel transmitter) B 18 + U m Positive measuring voltage A 19 U m Negative measuring voltage (0 V) B 19 FAULT Module fault (see PC Remote Monitoring under FAULT ) A 20 EX Enable signal for multiplexer B 20 SDA System bus (data) B 21 SCL System bus (clock) C 21 SDAI System bus (data) A 16 SCLI System bus (clock) A 18 A 0 Address line 0 for system bus A 22 A 1 Address line 1 for system bus B 22 A 2 Address line 2 for system bus C 22 A 0I Address line 0 for system bus A 17 A 1I Address line 1 for system bus B 23 A 2I Address line 2 for system bus C 13 RF IN Auxiliary signal input B 31 RF OUT RF output B 1 1 C 10 23 31 B A PCB Output level J 1 Attenuation (optical input) Mode Adjuster Remarks Jumpers for: Output level Attenuation (opt. input) Mode For setting the desired output level in 1-dB increments For adjusting the optical receiver to the current optical input power. Attenuation can be adjusted in 1-dB increments. The 0.5-dB jumpers are for fine adjustment of the output level Normally Auto, other settings intended for servicing and testing purposes only Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-5/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen

Data Sheet Remote Monitoring Parameter Remarks Display on PC monitor FAULT Power supply not present or incorrect Red LED Optical power too low RF level too low RF LEVEL Internal HF signal presen Green LED OPT. IN Optical input power sufficient Green LED REMOTE Telecontrol activated Green LED OPT. ALARM ORS receiving too little optical power Message via OTRS 60 return channel transmitter to OTS optical transmitter to reduce laser output Date 13.11.96 Name Dept. Product Description Product Number Sheet Optical Receiver ORS 600 960 736- BEH Optical Receiver ORS 800 960 810-6/6 This document is the property of Richard Hirschmann GmbH & Co. It may not be duplicated in any way whatsoever, commercially exploited, communicated or passed to third parties without our prior consent. Violation of these conditions shall render the perpetrator liable for compensation. All rights reserved in the event of issue of patents or registered designs. Richard Hirschmann GmbH & Co. Stuttgarter Straße 45-51 72654 Neckartenzlingen