ModBus 101

[KenC]

It has come the time for me to have a go at the ModBus thingy in Mach3.
Done my Google on the subject & hours of staring at the screen reading documents written in Sanskrit... :o

Would most appreciate if anyone could give me a jump start by explaining the followings terms in plain English?

Coil
Descrete Input
Holding Reg
Input Reg
Single Coil
Single Reg

Million thanks in advance.

[zumergido]

i have made a modbus,
coil its output like relays or other on off thing.
discrete input can be 0 or 5v input depends on the electronics. on off thing.
Holding Reg can have a value of 0 to 255 . usefull for pwm of control vfd driver
Input Reg its a 0-255 input. like potentiometer or voltage reading.

on mach3 this uses brains control.
you have some videos here http://www.machsupport.com/videos.php

https://lh3.googleusercontent.com/-NAPao2BXt6o/UIwv8mwsaNI/AAAAAAAAALE/dG9ikUtRhIk/s400/DSC00932.JPG
i have this controller
7 relays
10 digital inputs
1 pwm output
1 mpg input
3 analogical input.
works on serial rs232 i have some interference problems that i have to fix. beside that works great.
on the web you can find network modules, serial, rs485. all work the same.

[KenC]

Hi Fernanda,
Thanks for the heads up. Helps a lot!
Q's
When you say pwm out put, do you mean frequency output or Analog Voltage using PWM.