Reference Manual
748384-C
September 2003
I/O Modules Variables
Rosemount Analytical Inc. A Division of Emerson Process Management
3-16
NGA2000 Reference
IODIAG
Direction Output
Binding
None
Type
6-element enumerated array
Value range
Various
Units
Elements 1 and 3 - V; elements 2, 4 and 6 - mA; element 5 - Ohms.
Description
A10 and ACAL only; shows the operation of the analog output circuitry.
What the module is intending to put out as volts.
What the module is intending to put out as mA.
The measured output voltage..
The measured voltage on the current output terminals.
The current circuit load resistance as entered by the user.
The calculated output current based on elements 4 and 5.
Usage
Used as a diagnostic tool to determine how the analog output circuitry is doing.
Note that the precision of the output DAC (16 bits, a resolution of about 0.2mV) is
significantly greater than the measuring circuit (12 bits, a resolution of no less than
5 mV), so this is only a rough test of the quality of the output.
See also
IOLIM
Direction output
Binding
None
Type
5-element floating point array
Value range
-20 to +20
Units
Elements 1 -3, mA; elements 4 and 5, V.
Description
AID and ACAL only.
The lower limit for the 0mA output.
The lower limit for the 4mA output.
The upper limit for the 20mA output.
The lower limit for the 0V output.
The upper limit for the 5V output.
Usage
These are used to set the limits beyond which the output current or voltage will not
go, no matter what the value of PVA they are trying to track. For example, if the
value of PVA goes negative for some reason, the 4mA output will go below 4 mA.
It may be desirable to refuse to allow it to go below 3mA, thus keeping a 0mA
output as an indication of a fault in the I/0 module.
See also
ANALOGOUTPUT
IOMAINTHOLD
Direction Output
Binding
IOMAINTHOLD
Type Enumerated
Value range
DISABLED; ENABLED
Units None
Description
Determines how the I/0 module reacts to the value of OPSTATUS being 1,
indicating that the analyzer's menus are being accessed and thus that the analyzer
in maintenance.
Usage
If set to DISABLED, the output will track the PVA reading during maintenance.
If set to ENABLED, the output will hold at its last value as soon as the menus are
entered.
See also
IOHOLDCAL