Siemens S5-135U/155U Broken Wire Signal for Resistance Thermometers, Currents, Broken Wire at

Analog Input/Output Modules

9.5.10Broken Wire Signal for Resistance Thermometers

An open-circuit in the lines to a resistance thermometer is indicated as follows:

Broken Wire at

M+

M±

Pt 100

IC+

IC±

Module Reaction, Encoded Value

0

0

0

0

0

Error Bit E

1

1

1

1

1

	If the mode ªwithout broken wire signalº is selected on the module, an
	open-circuit of the resistance thermometer is indicated with an overflow.
	Unassigned channels can be used for voltage or current measurement if the
	current flow outputs relating to the particular measuring channel are shorted
	with a wire jumper. Without this jumper, the error bit would be set for this
	channel and the value 0 would be encoded.
Broken Wire	When set to ªresistance thermometer,º switch 7 of mode switch I of the 465
Monitoring	analog input module allows broken wire monitoring of the IC+ lines to the
	resistance thermometer (Pt 100 constant current supply). In the event of
	open-circuit of this line, the error bit is set as for the other lines.
	At the ªvoltage/currentº (mV/mA) setting, the IC+ lines are not monitored for
	broken wire. (The error bit is not set for an open-circuit of this line.) You
	should choose this switch setting if you exclusively measure voltages or
	currents.

9-66	System Manual
	C79000-G8576-C199-06