RAKESH GIRI Posted March 22 Report Share Posted March 22 Before we were using masibus 85xx temp scanner with vision 120 PLC but now we are using masibus 85XX+ Temp. Scanner with VISION 120 PLC over Modbus RS485.But PLC not communicating with scanner. We don't find the address for scanner in PLC program. Quote Link to comment Share on other sites More sharing options...
MVP 2021 kratmel Posted March 22 MVP 2021 Report Share Posted March 22 Please post order code for old and new temp scanner. For find modbus address please use Visilogic Modbus sample project from Visilogic Help. Quote Link to comment Share on other sites More sharing options...
RAKESH GIRI Posted March 23 Author Report Share Posted March 23 old scanner was 85xx new one is 85XX+AIANNNU11XNN Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted March 27 MVP 2021 Report Share Posted March 27 Quickly reading the scanner's manual there is reference to needing to use the available special program to set the scanner parameters. https://www.masibus.com/data-acquisition/multi-channel-scanners/8-16-24-channel-scanner-protection-relay-cum-data-logger-85xx/ Quote Link to comment Share on other sites More sharing options...
RAKESH GIRI Posted March 31 Author Report Share Posted March 31 how can I change slave ID address in visilogic program. masibus old scanner register is 400001 and masibus new scanner register is 300001. how to put new scanner register value in vision 120 PLC program. bn.vlp Quote Link to comment Share on other sites More sharing options...
Fernando Castro Posted March 31 Report Share Posted March 31 I think you are confusing the terms: slave ID is usually used to specify the device on the Modbus Network. in the code that you sent is hardcoded to be 1: register 400001 and 300001 to me sounds like different function code registers. are you sure that the Masibus Old and New scanner uses different addresses? some background on Modbus: Modbus works using specified registry addresses, and the called function codes: so, 30001 is the first address on the Input registers, and 40001 is the first one on the Holding registers. the difference is that holding registers are Read/Write and Input registers are only Read. so, if you want to access register 30001 you need to point to addres 0 of Input registers using function code 4 (Read Input registers). the program that you sent is accessing address 0 using function code 3 (Read Holding registers) which happens to be register 40001: If you are sure that you need to read register 30001 then use the appropriate function code: Also, some Modbus devices starts counting on 0, others on 1 just to take into consideration. 1 1 Quote Link to comment Share on other sites More sharing options...
RAKESH GIRI Posted April 1 Author Report Share Posted April 1 thank you so much sir for resolved my problem. Quote Link to comment Share on other sites More sharing options...
RAKESH GIRI Posted April 3 Author Report Share Posted April 3 On 3/31/2023 at 6:05 PM, Fernando Castro said: I think you are confusing the terms: slave ID is usually used to specify the device on the Modbus Network. in the code that you sent is hardcoded to be 1: register 400001 and 300001 to me sounds like different function code registers. are you sure that the Masibus Old and New scanner uses different addresses? some background on Modbus: Modbus works using specified registry addresses, and the called function codes: so, 30001 is the first address on the Input registers, and 40001 is the first one on the Holding registers. the difference is that holding registers are Read/Write and Input registers are only Read. so, if you want to access register 30001 you need to point to addres 0 of Input registers using function code 4 (Read Input registers). the program that you sent is accessing address 0 using function code 3 (Read Holding registers) which happens to be register 40001: If you are sure that you need to read register 30001 then use the appropriate function code: Also, some Modbus devices starts counting on 0, others on 1 just to take into consideration. Dear sir, we put the read input register (4) but also not communicated with scanner. Please find the attached photo and program. bn.vlp Quote Link to comment Share on other sites More sharing options...
RAKESH GIRI Posted April 3 Author Report Share Posted April 3 how can I change slave ID address in visilogic program. masibus old scanner register value is 400001 and masibus new scanner register value is 300001. we put new scanner register value in vision 120 PLC program but PLC not communicated with scanner. Please find the attached program, and please suggest me. bn.vlp Quote Link to comment Share on other sites More sharing options...
Gabriel Franco Posted April 3 Report Share Posted April 3 1. Do not place more than one rung in each net. Split them. 2. You´re using the same ID (#1) to master and to slave. Fernando already mentioned where to change slave ID address. It´s highly suggested to use Modbus PC software (such as ModScan, Modbus Poll or any other) to debug communications. Quote Link to comment Share on other sites More sharing options...
Fernando Castro Posted April 3 Report Share Posted April 3 On 4/1/2023 at 3:07 AM, RAKESH GIRI said: thank you so much sir for resolved my problem. So, I did not solved the problem? 😂. 2 hours ago, Gabriel Franco said: 1. Do not place more than one rung in each net. Split them. 2. You´re using the same ID (#1) to master and to slave. Fernando already mentioned where to change slave ID address. It´s highly suggested to use Modbus PC software (such as ModScan, Modbus Poll or any other) to debug communications. Good catch! from @Gabriel Franco. I assumed that the program was working as it was with another older scanner before. If that is the case, the process that I'll do to troubleshoot is first. check the hardware configuration. I have the feeling that the issue may not be the Modbus address that you are trying to read (30001 vs 40001). If it is RS485, then it is a serial communication is the scanner properly configured? (Baud rate, parity, data bits, timeout) does it require a terminator resistor? sometimes there is a configuration option or dip switch to set those. And following Gabriel, you can test on a computer using this Modbus Master simulator: Modbus Master Simulator - free software utility for testing Modbus slave devices (dxp.pl) Quote Link to comment Share on other sites More sharing options...
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