Help - Communication between FX3U & Q-Series

[sarvan 0]

Hello Guys I am using two Mitsi PLCs - 1 Q-Series & 1 FX3U. The FX3U is in a remote location monitoring a level and sending it back to the Q PLC. FX3U communicates with the Q PLC via a leased line using TD-36 Westermo Modems at each end. I am really confused about setting up the comms as both of them use different protocols. Also some instructions like MSG cannot be used with a FX3U. I am using GX IEC Developer 7.01 and hope to use RS2 instruction in FX3U to send the data. The FX3U is connected to the modem by a serial link RS-232. I am using FX3U-232-BD board, configured Ch1 as follows: Protocol - Non-procedural DataLength - 7 bits Parity - Even Stop bit - 1 bit Speed - 9600 H/W type - Modem/RS-232C Transmission - Form1 (without CR,LF) I am not sure if this will work. On the Q PLC, there is a QJ71C24-R2 Module that reads data from the modem at that end. I would appreciate any suggestions/advice. Thank you. Note: See attached jpeg file for system architecture.

[kaare_t 155]

Hi! None of the PLCs have the "Master" protocol (the one that actually polls data) in these cards, so this causes some problems for you. I see you want to use "Form1", which is a Mitsubishi protocol, the problem is that both these cards only have the Slave function implemented (they only work as a server, waiting for a client -master- to poll data from them). If I were you I would purchase a QJ71MB91 (Modbus RTU) card for the Q PLC, and simply set this up as a Modbus Master. Then you can use the Modbus Slave function block in the FX3U for the 232-BD card. Another option is to use fixed buffer/No-Protocol between the PLC's but then you'll have to do some more programming (all in all, I think that the QJ71MB91 will be a less expensive solution since you will cut down on development time). If you still wan't to use Fixed Buffer/No-Protocol, you'll have to set up NoProtocol in the serial cards (check bit-pattern in the correct buffer memories/switch settings), and then you can just send whatever data you would like.