Rockwell Automation 1762-Lxxxx MicroLogix 1200 Programmable Controllers - Manual (Page 78)

Publication 1762-UM001G-EN-P - March 2011
4-12 Communication Connections
Ground and Terminate the DH-485 Network
Only one connector at the end of the link must have Terminals 1 and 2
jumpered together. This provides an earth ground connection for the shield of
the communication cable.
Both ends of the network must have Terminals 5 and 6 jumpered together, as
shown below. This connects the termination impedance (of 120 ohm) that is
built into each AIC+ as required by the DH-485 specification.
End-of-Line Termination
Connect the AIC+ The AIC+, catalog number 1761-NET-AIC, enables a MicroLogix 1200 to
connect to a DH-485 network. The AIC+ has two RS-232 ports and one
isolated RS-485 port. Typically, there is one AIC+ for each MicroLogix 1200.
When two MicroLogix controllers are closely positioned, you can connect a
controller to each of the RS-232 ports on the AIC+.
The AIC+ can also be used as an RS-232 isolator, providing an isolation
barrier between the MicroLogix 1200 communications port and any
equipment connected to it (for example a personal computer or modem).
The following figure shows the external wiring connections and specifications
of the AIC+.
Jumper Jumper
Belden #3106A or #9842 Cable
1219 m (4000ft) Maximum
Jumper
AIC+ Advanced Interface Converter
(1761-NET-AIC)
3
2
4
5
1