Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 326)

Connecting to a Host E–8
Publication 2755-833
Figure E.6 Connecting NEMA Type 4 Decoder to DH485
Network
L
D
P
R
M
N
Shield
TxB +
TxA –
RS-485
Termina-
tion➁
Shield
Host Port
2755-NC17
on Decoder
Host RS-485 Port
*
*
*
*
* Pin designations depend
on host device.
Shield ➀
➀ Only one of the devices in the network must have the cable shield connected to chassis ground.
Do this by connecting shield to pin A instead of pin L.
➁ Enable line termination for the device at each end of the network. To enable line termination,
connect pins M and N together. For all other devices in the network, leave pins M and N open.
SIG GND SIG GND
TxB +
TxA –
The following parameters are fixed for DH485 communications:
•
8 Data bits
•
Even parity
•
1 Stop Bit