Spectrum Controls 1762sc-IF4OF4 - Manual (Page 31)

Chapter 3: Configuring the 1762sc-IF4OF4 for RSLogix 500 3-9
User’s Manual Pub. 0300247-01 Rev. C
output voltage or current (depending on the output type) down to the “Low
Limit” value.
O<x> = Over range flag bits: Applies to all input/output types.
Inputs:
When set to 1 indicates input signal is above the “High Range” value.
Module will continue to convert analog data to the maximum “High Limit”
value. Bit is automatically reset (0) by the module when the over range
condition clears.
Outputs:
When set to 1, indicates the output word value set by the user is above the
”High Range” value (determined by the format). The channel will output
voltage or current (depending on the output type) up to the “High Limit”
value.
LD<x> = Load Error: This applies only to output channels. If the channel is configured
for voltage, this bit indicates a short circuit. If configured for current, an open
circuit is indicated. The error bit is cleared (0) at the time the condition is
cleared.
OC<x> = Open Circuit: This bit is only valid for 1-5V, 4-20mA ranges. When set to 1,
an open circuit has been detected.
Inputs:
Open circuit detection is only available for input channels configured for
4-20mA current or 1-5V voltage. The remainder of the input ranges will
float near 0V or 0mA when an open wire condition occurs. For each input
channel, the user is given the option of reporting upscale or 0 (see
configuration words). For 4-20mA range, an open wire condition will be
set for any value less than 2.0mA. For 1-5V range, an open wire condition
will be set for any voltage below 0.5V. Thermocouple ranges will display
appropriate temperatures for an input voltage near 0V.
Note: A special case exists when channels 6 or 7 are configured to display
CJC temperature. If either channel is configured to display the CJC
temperature, the associated OC bit will indicate an open-circuit condition, if
one exists, for the CJC sensor itself.
Outputs:
Open circuit detection is available for output channels in current mode.
For current outputs, open wire may not be detected when the output is
driven at or near zero.
Note: Input word 3 will always display the raw CJC temperature in degrees
C, Engineering units, and so no channel configuration is needed.
Section 3.6
Module
Update Time
The module update time is determined by the number of input channels enabled and by
the filter frequency selected for each channel.
ADC Filter
Frequency
Filter Frequency
(-3dB point)
Conversion Time Module update
470 Hz 109 Hz 20 ms = sum of conversion
times for each
enabled channels
62 Hz 14 Hz 45 ms
17 Hz 4 Hz 135 ms
4Hz 1 Hz 495 ms