Spectrum Controls 1769sc-IF8u User Manual

Page 47

Chapter 4: Module Data, Status, and Configuration

Jumper setting for current type input

This includes all current type inputs (i.e. 0 to 20 mA and 4 to 20 mA)

Jumper setting for non-current type input

Includes input types such as thermocouples, RTDs, resistance and all
voltage ranges.

Module Configuration (Word 0)

Module configuration word C:e.0 contains the bits to enable or disable
cyclic calibration and the CJC sensor, for the module. It is also used to
indicate which temperature mode is preferred for the module when using
RTDs or thermocouples. Disabling cyclic calibration or the CJC sensor
(for thermocouple inputs) will reduce the total module scan time if
performance over accuracy is desired.

IMPOR

IMPORT

TANT

ANT

ANT If you are using engineering units x 1

data format and degrees Fahrenheit temperature units,

thermocouple types B and C cannot achieve full-scale

temperature with 16-bit signed numerical representation. An

over-range error will occur for the configured channel if it tries

to represent the full-scale value. The maximum representable

temperature is 3276.7°F.

The role of the cyclic calibration is to reduce offset and gain drift errors
due to temperature changes within the module. By setting bit 14 to 0, you
can configure the module to perform calibration on all enabled channels.
Setting this bit to 1 disables cyclic calibration.

You can program the calibration cycle to occur whenever you desire for
systems that allow modifications to the state of this bit via the ladder
program. When the calibration function is enabled (bit = 0), a calibration