Rockwell Automation 1769-IF4XOF2 Compact 8-Bit Low Resolution Analog I/O Combination Module - Manual (Page 54)

Publication 1769-UM008A-EN-P - November 2001
4-10 1769-IF4XOF2 Module Data, Status, and Configuration Channels
Enable/Disable Output Channel (EOx)
Word 1 bits 4 and 5 (EO0 and EO1) are defined as the output channel
enable/disable bits. EOx bits allow individual output channels 0 and 1
to be enabled or disabled. When a channel is not enabled, the module
does not produce current or voltage.
Program/Idle Mode Selection Channel 0 and 1 (PM0 and PM1)
These bits provide Program (Idle) Mode selection for analog output
channels 0 (Word 0 Bit 2) and 1 (Word 1 Bit 2).
•
Hold Last State (0) – When reset (to 0), this bit directs the
module to hold the analog output at the last converted value
when the module transitions from Run to Program Mode. This is
the default channel condition.
•
User-Defined Safe State (1) – When this bit is set (to 1) and the
module transitions to Program mode, the module converts the
user-specified integer value from the Channel x Program Value
Word (3 or 5) to the appropriate analog output.
Fault Mode Selection Channel 0 and 1 (FM0 and FM1)
FM0 and FM1 bits provide Fault Mode selection for analog output
channels 0 (Word 0 Bit 3) and 1 (Word 1 Bit 3). When this selection is
disabled [the bit is reset (0)] and the system transitions from Run to
Fault mode, the module holds the last output state value. This means
TIP
To improve performance and speed, disable unused
channels.
IMPORTANT
Hold last state is the default condition for the
module during a control system
run-to-program mode change.
TIP
MicroLogix 1500™ does not support the
analog output module’s default hold last state
function and resets analog outputs to zero
when the system enters the program mode.