- Emerson Remote Terminal Unit Instruction Manual

CI-ControlWave Express Service / 3-13
Figure 3-8 - COM1 & COM2 RS-232 Loop-back Plug/Wires
Figure 3-9 - COM3 RS-232 & RS-485 Loop-back Wires
Note: RS-485 Loopback can be achieved via CPU Switches SW3-1 & SW3-2 set ON
3.5.1.2 Serial Comm. Port External Loop-back Test Procedure
Connect an external loop-back plug or loop-back wires to the Communication Port to be
tested (see Figures 3-8 and 3-9).
1. Type "1," "2," "3," or "4" for the port to test.
2. Set baud rate to test to 115200 baud or ALL ASYNC and the number of passes to 5.
3. Click on RUN button next to External loop-back.
! Test responses:
a) Success - All sections of test passed
b) Failure - TXD RXD Failure
- CTS RTS Failure
! Execution time < 5 sec.
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