5/5/2011 3:36 AM | |
Posts: 15 Rating:
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[snip] ... My problem is : I ues the example project, connect PLC S7 312, CP341 (RS422/485 type) as modbus slave to DCS communication card (DCS as master) in 2 wire mode. I used example project with modify suitable hardware. On DCS site, the request light is blinking as it sent request command to PLC. But on PLC site, there are not any TXD or RXD blinking (when Power on, they are on for a few second as selt-checking, and then totally off). Could any body tell me the solution? Thank you in advanced. split from: Sample Project of S7300 PLC as Modbus Slave |
Last edited by: CS Moderator at: 5/6/2011 2:21 PMnew subject after splitting Last edited by: linhmoi at: 5/5/2011 8:36 AM |
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5/6/2011 2:46 PM | |
Posts: 3093 Rating:
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Hello Linhmoi, do you get any error message in the diagnostic buffer of the CP? Regards, Kaulquappe |
5/9/2011 11:30 AM | |
Posts: 15 Rating:
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Dear Kaulquappe, Thank for your kind slipt the topic and your reply. There isn't error message in the diagnostic buffer of the CP. The connection bewteen PLC and DCS is via pin 4,11 on CP341 and DCS communication card. On DCS site, it can be sure that all configuration correct. I attach the project as your refference. Pls give me your idea. Thank very much. AttachmentCp341tes.zip (745 Downloads) |
5/10/2011 4:50 PM | |
Posts: 15 Rating:
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Dear Kaulquappe, I'm sorry for not clear discription. Infact, Tx+ connect to Rx+, Tx- connect to Rx-. Here by attach connection drawing of PLC and DCS. I also tried connect to CP341 DCS R(B) pin 11.................Rx+ R(A) pin 4...................Rx- GND..........................GND but still no of Rx, Tx led light. DCS site:configuration 2 wire, baud rate 9600, Data bit 8, stop bit 1, parity: none AttachmentPLC DCS 2wire conenction.zip (687 Downloads) |
5/10/2011 5:35 PM | |
Posts: 3093 Rating:
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Hello Linhmoi, when you are sure, that the master addresses slave 2 it should work. I have modified your sample and attached it. I parameterized the ASCII driver, just to see what happens. Use that sample and look in the diagnostic buffer, whether an error message occurs (it should!). Regards, Kaulquappe AttachmentCp341tes1.zip (610 Downloads) |
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