chandrakcet

Hi All, Can I connect and communicate from the Built-in RS232 Port of CP1E-NA20DR-A PLC to the RS485 pins of Modbus Slave Device through Modbus-RTU Easy Master Protocol??? For RS232 to RS485 conversion I can use a converter in between PLC & Modbus slave device. 

Hi All, Can I connect and communicate from the Built-in RS232 Port of CP1E-NA20DR-A PLC to the RS485 pins of Modbus Slave Device through Modbus-RTU Easy Master Protocol??? For RS232 to RS485 conversion I can use a converter in between PLC & Modbus slave device. 

Hi All,  Here attached are the screenshots of my CP1E-NA PLC’s Modbus program, DM allocation and port settings.   My Modbus slave device has the Modbus Holding Registers of 40001-16 and 2 wire half-duplex RS485 Pins. I want to read these holding registers from Built-in RS232 Port of CP1E-NA. I am using RS232-RS485 converter for connecting PLC & my Modbus slave device. When I execute my program, I am getting the error code of 80H (A response was not received from the slave). But I can successfully read the holding registers of my slave from ModScan64 software in PC through the same RS232-RS485 converter. I have provided the correct RS-232 wiring from CP1E as per the hardware manual. Problem is from CP1E and I don’t know how to solve this. Please help me in this regard. Following are the details of my slave device: Slave ID: 1 Function Code: 3 Number of Registers: 16 Starting Address: 40001 Communication: RS485, Half-duplex Protocol: Modbus RTU Baud Rate: 19200 Parity: None Data Bits: 8 Stop Bits: 1 Flow Ctrl: None

Could anyone please tell me do we need to enter slave address, function code, etc., in 1250 to 1299. Also please tell me communication data format  which is starting at 1203.

Hi Innoaloe, Thanks for your reply. Yes, I agree with you for RS232 port and I have made the wiring correctly as per the CP1E's Hardware Manual. I need the communication data format which is starting at 1203 as well as the response data format which is starting at 1254. Here attached is the image shows DM area's allocation in my program. For this program, I am getting the error code of 80H in 1252.

Hi,Thanks for your reply. Yes, I have communicated with PC through this converter. It is working fine and I can read the holding registers of gateway using ICC Modbus Master Tool (which I downloaded from internet) For your additional information, here CP1E-NA is set as Modbus Master and gateway is set as Modbus Slave. In my gateway, there are DIs & DOs. My gateway is mapped to a wirelesss node through wireless radio communication. I switched on a DO in my gateway throuh. Now I am trying to read that status of DO from Omron PLC by setting it as master through Mobus-RTU Easy Master Function.

Hi,I am using CP1E-NA PLC, RS-232 to RS-485 converter(Make: BB-Electronics) and one wireless gateway(Make: Banner). I have wired the RS-232 port of PLC to converter and then to RS-485 points of gateway. As per the CP1E CPU Unit Software's User Manual, I have did the port settings, programming and DM area allocation. I am trying to read the holding registers of my gateway using the function code, 03. But in PLC, I am getting the error code of 80 (i.e. response was not received from slave) in A640.02 and didn't get any response data which is starting from DM1254. Also, in CP1E CPU Unit Software's User Manual, they have provided the DM area allocation for command not for response. Can someone please share the information to solve my problem.Regards,Chandru