BusWorks® 965EN Module User’s Manual Modbus TCP/IP mV/TC Input
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Acromag, Inc. Tel:248-295-0880 Fax:248-624-9234 Email:
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TC Break Detection
: Can be selected for Upscale or Downscale open
sensor or lead break detection. Break detent selection applies to all
channels simultaneously and cannot be disabled.
TC Input Bias Current
: ±25nA typical (TC break).
Thermocouple Reference (CJC):
Better than
0.5
C at 25
C (see
Note1 of Table 1). Ambient effect of the CJC is
0.01
C/
C typical.
Note:
Cold Junction Compensation may be switched off to permit the
direct connection of a mV source to the input for ease of calibration.
For best results, allow the module to warm up for an hour prior to
calibrating CJC.
TC Linearization:
Within
0.25
C of the NIST tables.
DC Voltage (See Table 2):
Can be configured for the bipolar DC voltage
range of
100mVDC or ±1V DC.
Input bias current:
25nA typical.
Voltage Input Reference Test Conditions:
100mV input range with
10mV span; Ambient Temperature = 25
C.
Input Over-Voltage Protection:
Bipolar Transient Voltage
Suppressers (TVS), 18V clamp level typical.
Accuracy:
TC accuracy is listed in Table 1. CJC accuracy is
0.5
C.
Voltage accuracy is better than
0.05% of span. This includes the
effects of repeatability, terminal point conformity, and linearization,
but does not include sensor error.
Measurement Temperature Drift:
Better than
60ppm/
C
(±0.006%/
C).
Analog to Digital Converter (A/D):
A
16-bit
-
converter.
Resolution:
Given in Table 2 below per applicable range.
Input Range
Effective Resolution
100mV DC
0.005% or 1 part in 20000
±1V DC
0.005% or 1 part in 20000
Thermocouples
0.1
C (0.18
F)
Input Conversion Rate:
80ms per input channel, 320ms for four input
channels, 480ms for six input channels, typical. Additionally, CJC
channels are read every 10 seconds (at 80ms each, 160ms for
two, or 240ms for three).
Input Filter:
Normal mode filtering, plus digital filtering optimized and
fixed per input range within the
-
ADC.
Input Filter Bandwidth:
-3dB at 3Hz, typical.
Noise Rejection (Normal Mode):
40dB @ 60Hz, typical with 100
input unbalance.
Noise Rejection (Common Mode):
140dB @ 60Hz, typical with 100
input unbalance.
Data Types:
Input range (±1V, ±100mVDC) - A 16-bit signed integer
value with resolution of 0.005%/lsb.
20000 is used to represent
100%. For example, -100%, 0%, and +100% are represented by
decimal values
–20000, 0, and 20000, respectively. Temperature
(TC Inputs) - A 16-bit signed integer value with resolution of
0.1
C/lsb. For example, a value of 12059 is equivalent to
1205.9
C, a value of
–187 equals –18.7
C. The maximum
possible temperature range is
–3276.8
C to +3276.7
C.
Analog Inputs
General Specifications
