Determining Open-Circuit Response (Bits 5 And 6); Cyclic Lead Compensation (Bit 4); Selecting Input Filter Frequency (Bits 0 Through 2) - Spectrum Controls 1769 User Manual

Not all controllers allow online configuration changes. Refer to your controller's user manual for details.
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During an online configuration change, input data for that channel is not updated by the module.
Chapter 3: Module, Data, Status, and Channel Configuration

3.2.7 Determining Open-Circuit Response (Bits 5 and 6)

An open-circuit condition occurs when an input device or its extension wire is
physically separated or open. This can happen if the wire is cut or disconnected
from the terminal block.
Bits 5 and 6 define the state of the channel data word when an open-circuit
condition is detected for the corresponding channel. The module overrides the
actual input data depending on the option that you specify when it detects an
open circuit. The open-circuit options are explained in the table below.
Table 3-4. Open-Circuit Response
Response Definition
Option
Sets the input data value to full upper scale value of channel
Upscale
data word. The full-scale value is determined by the selected
input type and data format.
Downscale Sets the input data value to full lower scale value of channel
data word. The low scale value is determined by the selected
input type and data format.
Last State Sets the input data value to the last input value prior to the
detection of the open-circuit.
Zero Sets the input data value to 0 to force the channel data word to
0.

3.2.8 Cyclic Lead Compensation (Bit 4)

For each channel, the module measures lead resistance in one of two ways. Set
bit 4 to 0 to enable measurement and compensation of lead resistance every 6
module scans. One channel is measured per module update to limit the impact to
channel throughput. You can also implement a lead wire calibration cycle any
time, at your command, by enabling and then disabling this bit in your control
program. Regardless of the state of bit 4, lead wire compensation occurs
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automatically on a system mode change from Program-to-Run or if any online
configuration change is made to a channel.

3.2.9 Selecting Input Filter Frequency (Bits 0 through 2)

The input filter selection field allows you to select the filter frequency for each
channel 0 through 5. The filter frequency affects noise rejection, cut-off
frequency, repeatability, and update time. The table below describes the effects
for each of the 6 user selectable filters.
The input filter selection field allows you to select the filter frequency for each
channel 0 through 5. The filter frequency affects the following, as explained
later in this chapter:
• Noise rejection characteristics for module inputs
• Cut-Off Frequency
• Repeatability
User's Manual Pub. 0300241-02 Rev. A
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