Rockwell Automation T8449 Trusted TMR 24V dc Valve Monitor Module - 40 Channel - Manual (Page 27)

Trusted
TM
Module T8449
Issue 13 Apr 10 PD-T8449 27
3.2.4. Rack 4: CI_MXDAT
The CI_MXDAT board returns the field loop current and MXDAT values for each field device.
Channel
Field
Device
Description
1 Control output current
2
1
MXDAT value
3 Control output current
4
2
MXDAT value
39 Control output current
40
20
MXDAT value
Table 10 Rack 4: CI_MXDAT descriptions
The current is the sum value taken from the triplicated module. The current level is reported as an
integer, with the units being
1 /
1000
A. 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 1000 to return the current 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 current. The full-scale range for this number format is decimal ±32, corresponding to physical
range –32000 to +32000.
The MXDAT value is dependent on the value of MXIN for the corresponding field device. A complete
list of data items (i.e. valid MXIN values) is provided after the rack definitions. The MXDAT value is the
median value taken from the triplicated module.
MXDAT values are only valid when MXOUT is equal to MXIN.
3.2.5. Rack 5: MXOUT
This board provides the connection to the MXOUT signal for each field device.
Channel
Field
Device
Description
1 1 MXOUT value
2 2 MXOUT value
20 20 MXOUT value
Table 11 Rack 5: MXOUT descriptions
Values written to MXOUT are sent to the module to request that specific data items be return via the
CI_MXDAT board. It will take one or more application scans after changing a MXOUT value before the
corresponding values MXIN and MXDAT will reflect the change. A complete list of data items (i.e. valid
MXOUT values) is provided after the rack definitions.
Writing invalid values to MXOUT (i.e. a value not specifically on the predefined list) will be result in
MXOUT being set to 0.
MXDAT values requested by MXOUT are only valid when MXOUT and MXIN are equal.