Rockwell Automation T8449 Trusted TMR 24V dc Valve Monitor Module - 40 Channel - Manual (Page 26)

Trusted
TM
Module T8449
Issue 13 Apr 10 PD-T8449 26
3.2.3. Rack 3: AI_MXIN
The AI_MXIN board returns the field loop voltage as well as the specific MUX data item index for the
corresponding MXDAT value for each field device.
Channel
Field
Device
Description
1 Control output voltage
2
1
MXIN value
3 Control output voltage
4
2
MXIN value
39 Control output voltage
40
20
MXIN value
Table 9 Rack 3: AI_MXIN descriptions
The voltage is the median value taken from the triplicated module. The voltage level is reported as an
integer, with the units being
1 /
500
V. This may be used directly, scaled arithmetically or scaled using the
IEC1131 TOOLSET conversion tables.
To scale the value arithmetically simply divide the returned ‘integer’ by 500 to return the voltage as
either a REAL or INTEGER as required.
The IEC1131 TOOLSET conversion tables may be used to convert the value to engineering units, in this
case voltage. The full-scale range for this number format is decimal ±64, corresponding to physical
range –32000 to +32000.
The MXIN value is an integer index that defines the meaning of the MXDAT value. A complete list of
data items (i.e. valid MXIN values) is provided after the rack definitions. The MXIN value is the median
value taken from the triplicated module.