Rockwell Automation GMLC Reference Manual - Manual (Page 472)

Publication GMLC-5.2 - November 1999
Remote Control 435
Multidrop
Multidrop is a communications scheme that allows multiple motion
controllers to communicate with each other over a single RS-422 serial
link. When using multidrop, serial port B of the master motion controller
is connected to serial port A of the slave controllers, as shown below.
If DH-485 is selected do not use this scheme of master slave multidrop.
Instead, you must daisy chain together serial ports A.
The GML Commander diagram in the master motion controller uses
Remote Control blocks to read variable values and/or status conditions
from a selected slave controller.
For proper operation, each slave motion controller must have multidrop
mode enabled, either in the General page of its Configure Control Option
dialog box or via an Adjust type command within a Control Setting block.
In addition, each slave motion controller must have a valid address
selected using the rotary
ADDRESS switch on the front panel. See the Setup
section of the Installation and Setup manual for your motion controller
for more information on enabling multidrop mode.
Master
IMC S Class
Motion
Controller
Slave “1”
IMC S Class
Motion
Controller
Slave “2”
IMC S Class
Motion
Controller
Port
A
Port
A
Port
A
Port
B
Port
B
Port
B