Regards,
Rob Wichterman
Inside Sales Engineer
HMS Networks
Email: rowi@hms.semailto:rowi@hms.se
Direct: (312) 598-2802
This is a Modbus RTU application.
Can you please repeat the question and resend any pictures because it looks like the important part of the email didn’t get forwarded to me.
Thank you!
I purchased the Communicator late last year and the plant is just now getting around to get this installed. I am a little confused by the wiring diagram for the RS485. Typically on a half-duplex Modbus RTU application there are only three wires terminated
(RS485+, RS485- & shield). Do I need to terminate the +5V across the resistors shown below or is this done internally?
The last picture is what I have available for terminations on the end device. I do not see a place to terminate the signal ground. Do I just not use this point?
Tim Dykema
Tri-City Engineering & Integration
You shouldn’t have to worry about that termination unless you are getting a lot of errors/noise on the bus. It’s usually only necessary with a longer bus with many devices.
Thanks, I assume you are referring to the signal ground? How about the 5V across resistors? Is that done internally?
Yes it is.