Emerson 644 manual Troubleshooting Guides, Troubleshooting guide

Rosemount 644

Reference Manual

00809-0400-4728, Rev AA June 2011

Troubleshooting Guides

Figure 3-1. 644 troubleshooting flowchart

PROBLEMS WITH COMMUNICATIONS

Device does not

appear on segment.

1.Check wiring to device.

2.Recycle power to device.

3.Electronic failure.

Refer to “Device does not show up on segment” in Table 3-2for more information.

Problem Identified?

Yes No

Perform Recommended

Action, see Table 3-2.

Device does not stay on segment.

Check Segment, see “Device does not stay on segment” in Table 3-2for more information.

Problem Identified?

	Yes		No
Perform Recommended		If the problem persists
		contact your local
Action, see page 3-6.
		Rosemount representative.

Table 3-2. Troubleshooting guide.

Symptom(1)	Cause	Recommended Actions
Device does not show up on segment	Unknown	Recycle power to device
	No power to device	1.	Ensure the device is connected to the segment.
		2.	Check voltage at terminals. There should be 9–32Vdc.
		3.	Check to ensure the device is drawing current. There
		should be approximately 10.5 mA nominal (11 mA max.)
	Segment problems
	Electronics failing	1.	Replace device.
	Incompatible network settings	Change host network parameters.
		Refer to host documentation for procedure.
Device does not stay on segment(2)	Incorrect signal levels.	1.	Check for two terminators.
	Refer to host documentation for	2.	Excess cable length.
	procedure.	3.	Bad Power supply or conditioner
	Excess noise on segment.	1.	Check for incorrect grounding.
	Refer to host documentation for	2.	Check for correct shielded wire.
	procedure.	3.	Tighten wire connections.
		4.	Check for corrosion or moisture on terminals.
		5.	Check for Bad power supply.
	Electronics failing	1.	Replace device.
	Other	1.	Check for water around the transmitter.

(1)The corrective actions should be done with consultation of your system integrator.

(2)Wiring and installation 31.25 kbit/s, voltage mode, wire medium application guide AG-140 available from the Fieldbus Foundation.

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