IOtech MultiScan 1200, User Manual

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TempScan / MultiScan User's Manual Chapter 13: System Operation 223
Open Thermocouple & Range Error Checking
The TempScan/1100 or MultiScan/1200 unit possesses built-in utilities for the detection of open
thermocouple and range errors on configured channels, as follows:
•
One hardware utility: The thermocouple cards contain circuitry to detect open thermocouples.
•
Two software utilities: The software detection routines are designed to detect if the input A/D
reaches its maximum value, and to detect if an input exceeds the linearization limits.
If an open thermocouple or a range error is detected, then Bit 5 in the Error Source Register (
ESC
) will
be set. In turn, Bits 2 to 7 (including Bit 5) in the
ESC
will together be mapped into the Execution
Error Bit (Bit 4) in the Event Status Register (
ESR
), denoting that this particular error condition exists.
The offending channel(s) can be determined by reading their values. If a channel is in error, its value
will be the following:
•
If a Thermocouple channel (assuming degrees Celsius):
±3276.70
.
•
If a Volts channel for the TempScan/1100 unit:
±32.7670
.
•
If a Volts channel for the MultiScan/1200 unit:
±005.767
.
Note:
Open thermocouple and range error checking is only performed on configured channels.
Software Digital Filtering (TempScan/1100 Only)
As a standard feature, the TempScan/1100 employs an advanced software digital filter to ensure quiet
and accurate thermocouple input. This feature is enabled as part of the factory default settings. With
the
Set Software Digital Filtering (
*W
) command, this digital filtering feature can be disabled in order
to improve reaction response time, or re-enabled to reinstate the feature.
For information on MultiScan/1200 noise filtering, see section Measuring Modes (MultiScan/1200
Only) in the chapter System Configuration .