Kingfisher Plus+ Hardware Manual
9. ANALOGUE INPUT MODULES
Analogue input modules provide analogue inputs to the Kingfisher Plus+ RTU.
Each module is equipped with a fully isolated 24 V
DC
power supply for energizing field
equipment such as sensor loops.
AI-1: 8 Channel Analogue Current Input Module
9.1.1 Overview
• 12 Bit resolution
• 1.5 kV Field to Logic Isolation
• 2 ms scan rate
• 24 V
DC
isolated DC output
• 0 – 20 mA or 4 – 20 mA current inputs
• 0 – 5 V
DC
or 1 – 5 V
DC
Voltage Inputs (requires factory modification)
The analogue input module provides eight input channels, each capable of converting an
analogue input signal to a digital variable for use as required by your application. A link on
the rear of the module selects 4-20 mA or 0-20 mA for all 8 channels. The default range is
4 to 20 mA.
The module can also be factory modified to handle voltage inputs of 0-5 V
DC
or 1-5 V
DC
.
Conversion speed for each of the eight channels is 20 µs and this provides a total update
rate of two milliseconds for the module. Resolution of the converted signal is 12 bits binary
(1 part in 4096) over the range. The placement of the 12 bits from the A/D converter in the
#AI data word is as follows:
MSB
LSB
0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 0 0 0
If the current source is reversed into the input, or is less than the low end of the current
range, then the module will output a data word corresponding to the low end of the current
range (0000H in #AI). If an input that is out of range is entered (i.e. greater than 20 mA), the
A/D converter will output up to full scale (corresponding to 7FF8H in #AI).
Hardware Manual Version 7.16
http://www.servelec-semaphore.com/
Page 131
To Next Page
Loading...