Siemens UM344-2 user manual Message Communication Error, Message No Transmitter Found

UM344-2CALIBRATION AND MAINTENANCE

TABLE 6.2	Message - No Transmitter Found, Continued
Possible Cause: Loop Power	Check power supply output voltage for installed network resistance:
Supply Failure	17 Vdc minimum at 250Ω
	42 Vdc maximum at 1100Ω
	Check power supply for blown fuse or tripped circuit breaker
Possible Cause: Transmitter	Replace Electronics Module. Refer to Section 6.5.2.
Electronics Module Failure

TABLE 6.3 Message - Communication Error

This message results when, after having successfully established communications with a transmitter, an error flag is detected in a received message and the message is not accepted. Error types are: Vertical Parity Error, Overrun Error, Framing Error, Longitudinal Parity Error, and Buffer Overflow.

POSSIBLE CAUSE	CORRECTIVE ACTION
Possible Cause: Noise on Loop	Press RETRY (F3) at least 3 times, waiting at least 1 minute between retries. If
Wires	not successful, continue troubleshooting
Loop Wiring Failure	Check for 12 Vdc minimum across SIGNAL +/- terminals in transmitter terminal
	compartment.
	Check polarity of loop wiring.
	Check that loop resistance is between 250Ω and 1100Ω to support HART
	communications.
	Check for loose or broken loop wiring at power supply terminals, Supply
	Barriers (if used), junction boxes, and transmitter terminal compartment.
	Check for disconnected or broken Current Sense Resistor.
	Check for short between cable shield and SIGNAL + loop wire.
	Check for accumulation of moisture in transmitter terminal compartment.
	Check for the proper type and length of loop cable and for electrical
	interference between the loop cable and any adjacent cables in a cable tray or
	conduit.
Loop Power Supply Failure	Check power supply output voltage: 17 Vdc minimum, 42 Vdc maximum.
	Check power supply for blown fuse or tripped circuit breaker.
Transmitter Electronics Failure	Replace Electronics Module. Refer to Section 6.5.2.

September 1995 6-21