201.028 REV 1 Date of Issue: 18 June 2018
− This is not the same thing as the "start signal delimited test" option ("start signal defines test duration" in
user settings when enabled). This is for using the start signal to control the duration of each *single* test,
only.
Other ways to test are:
− From the CMS front panel START button, if fitted (K Keyboard option)
− Via RMF-View or PLC Modbus command
− Periodic automatic testing according to a programmed test mode
6.1.2.6 Alarm Outputs
These are opto-isolated switches that can be used to signal external indicators, PLC inputs or other equipment
(e.g. pump on/off control).
The exact function of these outputs is determined by the Alarm Mode setting (section 6.3.3.9).
The outputs are "voltage free’’ contacts that can switch AC or DC signals up to 36V nominal (60V absolute
maximum peak voltage).
6.1.2.7 4-20mA Connection
See Figure 6.7 for a schematic.
The two 4-20mA outputs are sourced from the main supply voltage DC+. These may be connected to the 4-20mA
inputs of a process indicator or a PLC. The 0V connection is then also normally connected to the PLC 0V.
The 4-20mA outputs can be converted to 0-5V outputs by connecting a 250 ohm resistor between each output
and 0V. Similarly they can be converted to 0-10V outputs by connecting 500 ohm resistors.
For details of how the test results are represented by the 4-20mA signals, see section 6.4.3.
To Next Page
Loading...