Hello, sorry to join with a problem but going through the topics I see many helpful responses and am hoping someone can help me here! I am having difficult creating and sustaining a Modbus/Ethernet/MBP network involving: - A Modicon M340 CPU 2020 - 4 Schneider 7350 Powerlogic transducers connected via Modbus - A TCS EGD module to interface between Ethernet and MBP - A Momentum PLC connected via MBP The M340 requests data from the 4 meters continuously using 4 READ_VAR function blocks. It then analyzes the health data from the meters and stores either the data or 16#FFFF at a designated location to be read from the Station Master, the Momentum PLC. This occurs successfully (data is read from the M340 PLC and written to the Momentum PLC, and SER COM shows a flashing orange LED). However after approximately 35 -75 minutes (it varies) communication on the Modbus stops and, the communication times out with each of the meters, and the data stored becomes 16#FFFF as per the analysis. No Error lights appear ON the PLC LED’s, however the “SER COM” has ceased to flash orange. Unfortunately we are not on site and it is located 2 ½ hours away, so I cannot see what the ERROR report is (if anything) from the READ_VAR command – we were unable to simulate any error report by disconnecting a meter etc – or what the number of “no responses” or bus errors have occurred on the serial link. Are there any settings that may be causing this? At our location we are using the same program and trying to recreate the error; however we only have 2 meters available and thus far after 12 hours we still have communication (SER COM still flashing, minimal bus errors). Thank you for any help.