Error Signaling - WIKA T32. S Serie Manual De Seguridad

2. Safety

2.4 Error signaling

The model T32.xS temperature transmitter monitors the connected sensors and its
own hardware for errors. In the event of a known error condition the device generates
an error signalling current.
The response time from the sensor is a maximum of 90 seconds.
This implies the discovery of the following potential errors:
Sensor burnout
■
Sensor short circuit (only for resistance temperature sensors, not for thermocouples)
■
Inadmissably high lead resistance (not with duplex resistance temperature sensors)
■
The online diagnosis-test interval of the instrument should be a maximum of
35 minutes. This implies the discovery of the following potential device errors:
ROM error
■
EEPROM error
■
RAM error
■
Program-counter error
■
Stack-pointer error
■
Furthermore, the following monitoring functions are carried out continuously:
Logical program flow control
■
Internal communications error
■
Over sensor upper limit
■
Under sensor lower limit
■
Cold junction temperature outside permissible limits (only for thermocouples)
■
Duplex sensor drift monitoring (activated optionally)
■
Configuration error
■
Monitoring of the permissible device temperature (optional, activated by default for
■
SIL versions)
Monitoring of the output limits (optional, not activated by default for SIL versions
■
starting from 01.01.2011)
CAUTION!
The device's error signalling current (error current) is configured in
accordance with the following requirements:
Error current fail high (high alarm value):
■
settable in the range ≥ 21.0 mA to ≤ 23.0 mA (upscale)
Error current fail low (low alarm value) :
■
settable in the range ≥ 3.5 mA to ≤ 3.6 mA (downscale)
WIKA safety manual temperature transmitter T32.xS
GB
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