Rockwell Automation 1747-KE,D17476.12 DH-485/RS-232C Interface Module - Manual (Page 30)

Publication 1747-UM005B-EN-P - March 2006
3-4 Communicate with the Interface Module
Local Mode
Remote Mode
The valid range of slave addresses on a half-duplex network is 000
through 376 octal (000 through 254 decimal) accommodating a total of
255 devices. The valid range of addresses on a DH-485 network is 00
through 37 octal (00 through 31 decimal).
To let addressing of up to 255 DH-485 nodes, eight groups (group
numbers 00 through 07) of DH-485 networks are established. Each
group number defines a DH-485 network, which can consist of up to
32 nodes each (except for group 07 which is limited to 31 nodes).
Refer to the table on page 3-6.
During configuration of the interface module, the module’s group
number is selected if Remote mode has been selected.
In remote mode, the module appears transparent to the half-duplex
master, so that remote SLC 500 controllers can be polled directly as
individual slaves on the half-duplex network. The interface module
responds to the half-duplex master if the station address specified
corresponds to the node address of any (token-passing) station on
the DH-485 network connected to that interface module.
SLC 500
Node 02 SLC 500
Node 01
SLC 500
Node 03
SLC 500
Node 00
PLC 5
controller
DF1 Master RS-232C DF1
DH-485
DH-485
Link Coupler
((1747-AIC)
Link Coupler
((1747-AIC)
Link Coupler
((1747-AIC)