Application on Control Technology

Transcription

1 Application on Control Technology Programming example in Ladder Logic

2 Warranty, liability and support Note The application examples are not binding and do not claim to be complete regarding the circuits shown, equipping and any eventuality. The application examples do not represent customer-specific solutions. They are only intended to provide support for typical applications. You are responsible in ensuring that the described products are correctly used. These application examples do not relieve you of the responsibility in safely and professionally using, installing, operating and servicing equipment. When using these application examples, you recognize that Siemens cannot be made liable for any damage/claims beyond the liability clause described. We reserve the right to make changes to these application examples at any time without prior notice. If there are any deviations between the recommendations provided in these application examples and other Siemens publications - e.g. Catalogs - then the contents of the other documents have priority _.doc Warranty, liability and support We do not accept any liability for the information contained in this document. Any claims against us - based on whatever legal reason - resulting from the use of the examples, information, programs, engineering and performance data etc., described in this application example shall be excluded. Such an exclusion shall not apply in the case of mandatory liability, e.g. under the German Product Liability Act ( Produkthaftungsgesetz ), in case of intent, gross negligence, or injury of life, body or health, guarantee for the quality of a product, fraudulent concealment of a deficiency or breach of a condition which goes to the root of the contract ( wesentliche Vertragspflichten ). However, claims arising from a breach of a condition which goes to the root of the contract shall be limited to the foreseeable damage which is intrinsic to the contract, unless caused by intent or gross negligence or based on mandatory liability for injury of life, body or health The above provisions does not imply a change in the burden of proof to your detriment. Copyright 2006 Siemens A&D. It is not permissible to transfer or copy these application examples or excerpts of them without first having prior authorization from Siemens A&D in writing. For questions about this document please use the following address: mailto:csweb@ad.siemens.de V /05/08 2/7

3 Warranty, liability and support Table of Content Table of Content Summary of FC1 Functions: Modifying Your Application for Other Time Types _.doc Reference to Automation and Drives Service & Support This entry is from the internet application portal of Automation and Drives Service & Support. The documentation has the entry ID Click the link below to directly display the download page of this document. All entries referenced in this document are designated by their entry ID and addressed via the above path. V /05/08 3/7

4 Summary of FC1 Functions: Monitoring a Maximum Time Fault with an On Delay Timer Objectives: Using a timer output for a specific task Using clock memory to create a flashing light Using a Set/Reset to latch a fault condition 1 Summary of FC1 Functions: _.doc 1. Network 1: Start/Stop Circuit: I0.0 is used to simulate a momentary contact push button, and I0.1 is used to simulate Emergency Stop push button, which is a normallyclosed (NC) field device. Based upon the signal state from the field, I0.1 is already powered. When the signal state of I0.0 changes from "0" to "1", Q0.0 will be powered. Q0.0 then latches the start circuit on the next scan cycle. 2. Network 2: On Delay Timer Operation When the signal state of Q0.0 changes from "0" to "1", the timer T1 will be started. If the time of 15 seconds elapses and the signal state at input Q0.0 is still "1", the output Q0.1 will be "1". If the signal state of Q0.0 changes from "1" to "0", the timer is reset regardless of whether the timer is running or not. 3. Network 3: Time Fault Set-Reset Flip Flop: Note The Set-Reset Flip Flop box provides exclusive control of a bit; you can only turn the bit on and off with the Set and Reset functions. Once a bit is powered with the Set function, the Reset function is required to turn it off. In this example, the Set-Reset is used to set a bit (M3.3 in Network 4) that is turned on and off every.5 seconds (2 Hz), which in turn pulses a digital output. If the signal state is "1" at input Q0.1 and "1" at I0.1 (NC), memory bit M12.0 is set and output Q0.2 is "1". Otherwise, if the signal state at input Q0.1 is "0" and at I0.1 (NC) is "1", memory bit M12.0 is reset and output Q0.2 is "0". If both signal states are "0", nothing is changed. If both signal states change to "1" at exactly the same time, the reset instruction dominates because of the order; M12.0 is reset and Q0.2 is "0". V /05/08 4/7

5 Summary of FC1 Functions: 4. Network 4: Time Fault with a 2Hz Flashing Light (Bit 3, CPU Clock Memory): If the time of 15 seconds is exceeded, a fault is indicated. Disturbances are displayed with a 2 Hz flashing light (bit number 3 of the CPU clock memory byte MB3) at output Q0.3. The timer and time fault bit can be manually reset by power cycling I0.1. Note The Clock Memory function is like having eight built-in timers available for your applications. The clock memory byte is selected in the Hardware Configuration for the CPU. Under the CPU Object Properties, select: Cycle/Clock Memory tab > Clock Memory field. Check the Clock Memory checkbox and enter the required Memory Byte (MB) _.doc V /05/08 5/7

6 Modifying Your Application for Other Time Types 2 Modifying Your Application for Other Time Types This example uses an On Delay Timer. Five different timers are available for your use. There five variations are as follows: Pulse Extended Pulse On Delay On Delay Stored Off Delay _.doc The time period range for all five timers is between 10ms and 9990sec. Time values are entered in the S5T# data format (for example, S5T#2h10m30s or S5T#2s500m). Resolution depends on the size of time value used, with the maximum resolution being 10ms. Picture 2-1 Behavior of the Five Timer Types V /05/08 6/7

7 Modifying Your Application for Other Time Types _.doc Table 2-1 S_PULSE (Pulse timer) Timer S_PEXT (Extended pulse timer) S_ODT (On-delay timer) S_ODTS (Retentive on-delay timer) S_OFFDT (Off-delay timer) Description The maximum time that the output signal remains at 1 is the same as the programmed time value t. The output signal stays at 1 for a shorter period if the input signal changes to 0. The output signal remains at 1 for the programmed length of time, regardless of how long the input signal stays at 1. The output signal changes to 1 only when the programmed time has elapsed and the input signal is still 1. The output signal changes from 0 to 1 only when the programmed time has elapsed, regardless of how long the input signal stays at 1. The output signal changes from 0 to 1 only when the programmed time has elapsed, regardless of how long the input signal stays at 1. V /05/08 7/7