Rockwell Automation 61C613 16 Channel Analog Input Module - Manual (Page 21)

4Ć5
Before you attempt to define the signal type, you must first set the
module's channel register pointer to the desired value. Refer to
section 4.2.3 for more information. The configure channel input
command contains the following information:
Location (M+0) 10
Location (M+1) Channel Config Code
Location (M+2) 0
4.2.5 Configure Channel Slope
The configure channel slope command is used to define a slope
value for an analog input channel. If the slope is not defined for a
channel, the default is 1. The module will multiply the converted
analog value by the slope.
This feature is typically used to read small analog input voltages so
as to maintain useful digital resolution. For example, if you have
specified an input signal range of +25.0 mV, the digital values will
range +25 counts. If you define aslope of 1000, then the digital
values will range +25000 counts. Since the input circuitry can resolve
up to 14 bits, this results in useful information.
This feature can also be used to change the voltages from the
61C615 RTD Termination Panel into temperatures. Use 200 as the
slope in location (M+2) to read the input in degrees C and 36 as the
slope to read the input in degrees F.
Before you attempt to configure the slope, you must first set the
module's channel register pointer to the desired value (refer to
section 4.2.3). The command to configure channel slope contains the
following information:
Location (M+0) 16
Location (M+1) ls byte of slope
Location (M+2) ms byte of slope
ls = least significant
ms = most significant
4.2.6 Configure Channel Offset
The configure channel offset command is used to define an offset
value for an analog input channel. If the offset is not defined for a
channel, the default is 0. The module will add the offset to the
converted value after the value has been multiplied by the slope.
You can use nonĆzero values of offset to generate user units from
inputs corresponding to 4Ć20 mA signals, or from other signals with
known and fixed offsets. This feature must also be used to read RTD