Need help for modbus communication in ML1200

[JaiDutt]

Hello everyone,
M using micrologix 1200 and it is connected to net-aic using pm02 cable, then net-aic is connected to my laptop using pm02 and a serial to usb convertor, i have connected the energy meter to net-aic using single pair shielded cable at RS485 port. now m trying to read data from meter using msg instruction bt m not able to get the data. m attaching pic of my program . please help me out,

thanks

 

[Kidblue]

Hi,

There may be other things you need to check, but the first thing is your port settings. It doesn't look like you have set your channel to Modbus Master. I posted a couple of screen shots a couple of days ago that may point you in the right direction...

Rob

 

[JaiDutt]

Thanks bt still no success

I have made a few changes in configuration as the images attached....
please tell me where i m going wrong.

thanks

 

[Kidblue]

Hi,

You will need to check the protocol settings of your Slave device (Baud Rate/Parity/Stop Bits etc) and then when prompted during the download 'Apply' these settings. I presume you are connecting to the 2nd port (HMI/Programming) of the ML1200 with your laptop/PC?

Regards,

Rob

 

[JaiDutt]

then

img1 = plc type
img2 = channel 0 config
img3 = program
img4 = msg setup screen
img5 = error while downloading

i pressed dont apply
program got downloded and it showed error as in img6

 

[JaiDutt]

where is 2nd port?

 

[JaiDutt]

i have checked the comm setting of meter,
add=2
baud=9600
s=1
p=none

 

[JaiDutt]

when i press apply... everything hangs
then i have to reset comm of plc

 

[Kidblue]

Hi,

Are you saying you only have one port on the Micrologix 1200? If so, you are going to find this a little tricky to achieve! There is a dual port ML1200 that has a fixed 2nd port (DF1/19.2K) that you would use as your programming port and the other port would be set to your Modbus parameters. If you only have one port and you apply your protocol settings you will inhibit all communication via your laptop...

Regards,

Rob

 

[JaiDutt]

plc is 1762-L24BWA C

 

[JaiDutt]

ya dats y it gets hang

so what should i do now :O

 

[Kidblue]

Hi,

I'm not sure of budgets etc and why the ML1200 was selected, but if it needs to be AB and you can change the base unit, you will find the ML1100 far easier to work with. It has an RS485 port (so no AIC needed) and also has an ethernet port so programming is very accessible while CH0 is configured for Modbus...

Regards,

Rob

 

[JaiDutt]

i think it is ml1200 ser c with only one com port

 

[JaiDutt]

earlier i had done this with ml1400 it also has 3 ports so dat was a success. now m stuck with this. is it possible to do this with one port

 

[Kidblue]

Hi,

Once you set the port to Modbus, you will no longer be able to communicate with RSLogix500.

Regards,

Rob