Spectrum Controls 1746sc-INO4vi User Manual

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Chapter 4: Using Your Output Module

Reset Output Or Hold Last Value On Fault
(configuration bits 7 and 15)

Use this bit to select how your module responds to a fault:

• If you set this bit to 1, your module holds the output signal at its last

value when it detects a fault.

• If you set this bit to 0, your module resets the output signal to the

power-up setting (0 V or 0 mA) when it detects a fault.

Optional: Setting The
Output Data Limits (or
User-Defined Scale)

Words 6 and 7 of the output image file (addresses O:e.6 and O:e.7) let
you define either:

• the low and high values of the output data limits

• the low and high values of the user-defined scale, if the User-Defined

Scale data format is selected

Low Value of Output Data Limit (or User-Defined Scale)

O:e.6

Address

High Value of Output Data Limit (or User-Defined Scale)

O:e.7

If you do not want to use user-defined scaling or output data limiting, set
output words 6 and 7 to zero. Setting output words 6 and 7 to zero
disables output data limiting and invalidates user-defined scaling.

Because they share the same output words, you cannot use output data
limiting with the User-Defined Scale data format.

Important – The values in output words 6 and 7 apply to all four
channels. If you want to use user-defined scaling or output data limiting,
you must set all four channels to the same data format.

Output Data Limits

For added safety, the 1746sc-INO4i and 1746sc-INO4vi output modules
let you define limits for the values in the output data words of all four
channels. These data limits, in turn, limit the output signals that your
module provides. When an output data word exceeds the data limit, the
output value is truncated to the limit.

You can use output data limiting to prevent PID loops from exceeding
safety limits, to prevent operators from inadvertently setting incorrect
values, etc.

To properly enable output data limiting, the low and high output limits
(output words 6 and 7, respectively) musts be non-zero and non-equal,