Siemens UM344-2 user manual Message Field Device Malfunction, Possible Transmitter Output Problems

CALIBRATION AND MAINTENANCE UM344-2

TABLE 6.4 Message - Field Device Malfunction

This message results when, after having successfully established communications with a transmitter, a transmitter self-diagnostics failsafe flag is detected in a received message. Use the MXC STATUS program to identify the error source.

POSSIBLE CAUSE	CORRECTIVE ACTION
Transmitter Failed Self-Diagnostic	Press the STATUS key on the MXC. Confirm that the message "FAILSAFE"
Test	appears in the upper right corner of the display.
	With transmitter in FAILSAFE mode, see paragraph A of this section and
	perform steps 3 to 5.

6.3.2.2 Possible Transmitter Output Problems

In this section, Tables 6.5 through 6.9 provide information on diagnosing several types of analog output malfunction symptoms. Under each symptom, possible causes are identified and corrective action suggested.

TABLE 6.5 Symptom - Zero or Low Output

POSSIBLE CAUSE	CORRECTIVE ACTION
Transmitter accidentally configured	Configure transmitter for Analog Mode by changing its short address to zero;
for Digital Mode. Output current	See Section 3.
reads a constant 4.000 mA.
Transmitter Electronics Failure	Determine if transmitter communicates with MXC by executing FIND XMTR
	program on MXC; see Section 3. Refer to Section 6.3.2.1, paragraph B, to
	troubleshoot a communications failure.
	Check transmitter STATUS. If a FAILSAFE message is posted, refer to
	Section 6.3.2.1, paragraph A, for troubleshooting procedures.
	If transmitter STATUS checks OK, at the Main Menu, select LOOP OVRD
	(loop override). Verify the loop by setting the output current to 4, 12 and 20
	mA. If an Digital Meter is not installed, verify current by connecting an
	ammeter to the transmitter’s TEST +/- terminals.
	If the measured selected loop currents are significantly low in value, or loop
	current cannot be set, replace the Electronics Module. See Section 6.5.2.
	If transmitter passes loop override test, transmitter electronics are OK.
	Continue troubleshooting.

6-22 September 1995