Posted 2 Jan 2006 We use MSTR blocks for reading registers from one PLC to another. We use MODSOFT. How do I have to check if a communication error occurs? -Is it enough to use the middle output of the MSTR block? -Maybe better to read a register of a counter from the remote PLC and checking if the value changes? -Maybe better to read the Error register of the MSTR block? Share this post Link to post Share on other sites
Posted 7 Jan 2006 I have only ever used the 'error' o/p from the MSTR block. If you wanted to take different actions based on the actual error type then directly accessing the error register would be the way to go. From my experience I just moniter the error o/p and retry. The most common causes of errors are; 1 - poor cabling/termination. 2 - using more than 4 blocks active at one time. 3 - poor cabling/termination Other than this I can't say i've ever had any problems just monitering the o/p. Share this post Link to post Share on other sites