Emerson Rosemount 56, Instruction Manual

Page: 117 / 136

Profibus Communications 107
Instruction Manual Section 12: Profibus Communications
LIQ-MAN-56 April 2017
Table 12-14. Signal Board Diagnostic Bits – continued
Temperature Faults and Warnings
Signal
Board 1 / 2
GSD
Descriptor
Help
48 / 80 SN 1/2 RTD
Open (Fault)
The temperature measuring circuit is open. The RTD is improperly wired or the RTD IN or
RTD RTN are broken.
1. Check RTD wiring connections.
2. Check RTD for open or short circuits.
49 / 81 SN 1/2 RTD
Out Of Range
(Fault)
The resistance of the temperature sensing element (RTD) is too large or too small. The
sensor is wired improperly, or the temperature sensor is not recognized by the sensor board.
1. Check sensor wiring.
2. Check that the temperature sensing element is compatible with the analyzer. It must
be a Pt 100 or Pt 1000 RTD or a 22k NTC thermistor.
105 /
137
SN 1/2
Temperature
High
(Warning)
pH and Amperometric Measurements
The measured temperature is greater than 155 °C.
1. Check wiring.
2. Disconnect the sensor and check the resistance between the RTD in and RTD return
wires. It should be about 110 ohm at room temperature.
3. Replace the sensor if the RTD has failed.
Contacting Conductivity Measurements
The measured temperature is greater than 300 °C.
1. Check wiring.
2. Disconnect sensor and check resistance between RTD in and RTD return wires. It should
be about 1100 ohm at room temperature.
3. Replace sensor if RTD has failed.
Toroidal Conductivity Measurements
The measured temperature is greater than 200 °C.
1. Check wiring.
2. Disconnect sensor and check resistance between RTD in and RTD return wires. It should
be about 110 ohm at room temperature.
3. Replace sensor if RTD has failed.
106 /
138
SN 1/2
Temperature
Low
(Warning)
pH and Amperometric Measurements
The measured temperature is less than -20 °C.
1. Check wiring.
2. Disconnect the sensor and check the resistance between the RTD in and RTD return
wires. It should be about 110 ohm at room temperature.
3. Replace the sensor if the RTD has failed.
Contacting and Toroidal Conductivity Measurements
The measured temperature is less than -40 °C.
1. Check wiring.
2. Disconnect the sensor and check the resistance between the RTD in and RTD return
wires. It should be about 110 ohm at room temperature.
3. Replace the sensor if the RTD has failed.
107 /
139
SN 1/2 RTD
Sense Line
Open
(Warning)
The analyzer uses the sense line to correct for the resistance of the RTD leads and for
changes in the lead wire resistance caused by variations in ambient temperature.
1. Check wiring.
2. Disconnect the sensor and check for continuity between the RTD return and RTD
sense leads at the sensor.
3. If sensor has failed, use a wire jumper to connect the RTD sense and return terminals.
4. Replace the sensor.