Safety – WIKA T32.xS User Manual
Page 9
GB
9
WIKA safety manual temperature transmitter T32.xS
11583631.02 11/2010 GB/D/F/E
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)
2. Safety