Hi Experts,

I have checked following sequence with the Modbus ascii protocol with CP-341

• Connected two slaves with the loop cable

• Changed the address for two device  - one device address changed to 2 and another one is 18

• Read the temperature value from the device (Thermon) by the help of Modbus poll software and RS-232 to USB convertor  -  It was worked fine and  I read the temperature for the two device.

Hardware- Detail - CP-341- 6ES7341-1CH02-0AE0

CPU -314c-2PN/DP - 6ES7314-6EH04-0AB0

• PLC hardware parameter for communication – I used the same baud rate, parity and stop bit which one was communicated with Modbus poll.

• Downloaded the software and I have checked . in the PLC i am getting error

• Error ID showing 16#301
  

15 Bin connector was used

PIN Configuration 4,11,8-GND

Can you please help me to solve the problem.

Hello,

ok, first for sure some informations we need to know to hope not missunderstand some names and options. What simulator and what exact protocol you've set (you can post Picture of sim with that options)? What exact dongle with what protocol and driver selection you have bought for your CP341? Only for sure also, what exactly order number/type of that Modbus Device Thermon (we can check options for that device)?

HI,

I have using Modbus ASCII Protocal.

Modbus Poll software i have used to get the data's. It was working fine.

I have Problem during communicate with PLC.

Please find the Parameter setting screen shot for modbus poll and Step-7

Hello,

sry don't see all your pictures, you can zip them and attach zip file in case of more pictures, this is better system. Ok, what about that question about dongle?

Update: did you look to documentation about that error code what mean?

HI,

Can i know , do really need the dongle for the ASCII protocal. If we using modbus RTU that time only we need Doggle. correct. i donot about this so i am asking.

yesterday i got the 16#301 error. in the manual it was showing parameter error or wiring error

i have modified the program for the communication that program i didnot checked. today only i am going to check. so if have error please update me.

Here i have attached the program and the screenshot. if my program have any error please update me

Hello,

ok again, therefore I ask if you understand difference between Modbus ASCII and standard ASCII protocol. Again, I don't see Picture in your post only in zip file, so pls don't put pictures to post only in attachment. Sry I don't have time to check your prj, therefore I ask about settings. Your Slave device support Modbus RTU and Modbus ASCII protocol, simply you can  select these 2 different protocols in Slave device cfg? Can you pls again post info about your Slave device type (I want check it on internet)? Check again what drivers can download/select to CP if you want Modbus communication, chgeck Siemens site for this for sure.

Update: ok another question, you've mentioned from yesterday you have error, so you have communication established before with Slave via Modbus ASCII protocol and your CP341?

Hi,

Sorry. no modbus ASCII. it was  ASCII protocol.

Slave device accept ASCII protocol

Update: ok another question, you've mentioned from yesterday you have error, so you have communication established before with Slave via Modbus ASCII protocol and your CP341?  - i have used ascii protocal. with cp-341 it was showing error.  ASCII it was working in modbus Poll software

Device detail is - TC202a , Manufacture is Thermon

Hello,

but as I expected, you probably missunderstand this, there is difference with Modbus ASCII and standard ASCII protocol. Your Slave device accept only Modbus ASCII protocol, not standard ASCII protocol. Your posted Modbus poll SW has implemented this Modbus ASCII protocol, therefore probably you had data from Slave with that test. If you want implement also your CP341 as Modbus ASCII Master, you need Modbus ASCII driver and dongle. Link:

https://support.industry.siemens.com/cs/document/25362836/cp341-loadable-modbus-ascii-(16-bit-32-bit)-master-driver-?dti=0&lc=en-WW

Pls, this is very specific problem, pls give for sure Support request to your Siemens partner. This isn't simple as you expect. If you're skilled in serial communication programming, you can implement your own Modbus ASCII communication, then you don't need Driver and dongle.

hi,

ok thanks for your concerns

tomorrow i will check with the dongle and update you what is status.

Hello,

thank you also for your info, pls post result for sure, also I'm curious about that.