Perform A 700 Core Processor Resistance Test - Emerson Micro Motion 2500 Configuration And Use Manual

Troubleshooting
Table 12-9: Enhanced core processor LED states
LED state
12.32

Perform a 700 core processor resistance test

Note
You can perform a resistance test only on a 700 core processor.
Procedure
1.
2.
3.
4.
5.
Postrequisites
To return to normal operation:
1.
2.
3.
Note
When reassembling the meter components, be sure to grease all O-rings.
196
Description
Core processor internal failure
Power down the transmitter.
Remove the core processor lid.
At the core processor, disconnect the 4-wire cable between the core processor and
the transmitter.
Measure the resistance between core processor terminal pairs 3–4, 2–3, and 2–4.
Terminal pair Function
3–4 RS-485/A and RS-485/B
2–3 VDC– and RS-485/A
2–4 VDC– and RS-485/B
If any resistance measurements are lower than specified, the core processor may
not be able to communicate with a transmitter or a remote host. The meter may
need factory service.
Reconnect the 4-wire cable between the core processor and the transmitter.
Replace the core processor lid.
Restore power to the transmitter.
Micro Motion Model 2500 Transmitters with Configurable Input/Outputs
(continued)
Recommended action
The meter requires factory service.
Expected resistance
40 kΩ to 50 kΩ
20 kΩ to 25 kΩ
20 kΩ to 25 kΩ