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| Parameter | Units | RS485 | 4-20mA | Digital VFC | Notes |
|---|---|---|---|---|---|
| Instantaneous Resistance to Earth | k Ohm | This is the last reading of Resistance-to-Earth taken by the isometer | |||
| Alert Levels | k Ohm | The isometer permits two configurable alert thresholds. These levels are both reported | |||
| Alarm Status | Digital | Reports if either alarm level has been breached | |||
| Fault Repeat Relay Status | Digital | Reports if output fault relay has been energised. Essentially mirrors alarm status | |||
| Connection Error | Digital | Set to UP or TRUE is not no RS485 data has been received from the isometer for 7 minutes. | |||
| AC, DC+, DC- Fault | Digital | For DC Systems, Indicates which leg is experiencing the worst fault. For AC systems, only the AC flag will be asserted. | |||
| Fault Evaluator Output | Digital | Where a fault evaluator is provided and a single isometer monitors a multiple-feeder arrangement, a digital volt-free-contact output is provided for each feeder. The feeder experiencing the worst fault will have its contact closed. |
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| Info |
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The diagram on the left shows direct connection. Please consult the Bender user guide for exact terminations. Note that if the isometer is built into a Network Rail style cubicle arrangement, the "common" VFC connection is brought-out at the base of the cubicle through the terminal block position 37. The 12 individual feeder alarm signals are presented on terminal 38 (Feeder 1) through to 49 (Feeder 12). This is shown on the right |
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Configuration &
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Setting up the Channels
Rs485
Commissioning
Initial Setup
RS485
These steps may be completed on the SA380TX touchscreen, or via web-based configuration tool.
1) Set the RS485 "owner" to "Bender". This tells the SA380TX what type of device is attached to the RS485 port
TOUCHSCREEN - CONFIG TOOL
2) Create a "Bender" slave unit. The SA380TX needs to be explicitly told about devices attached to the RS485 port. Remember, only a single isometer may be connected at any one time.
TOUCHSCREEN - CONFIG TOOL
This will "Create" slave analogue and digital channels3 ) Check that the "Slave" has been successfully created
The SA380TX will create additional slave channels representing the data obtained over the RS485 interface. The screen grab below shows these channels in the web-based configuration tool. They will also be visible in the real-time displays and historic data logs accessible via the touch-screen,
WEB CONFIG OF CHANNELS
4) Check that the isometer device is active:
To verify that the isometer is sending data over RS485 and that the wiring is correct
| Info | ||
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If no RS485 data is visible: Be patient. isometers may take up to 2 minutes to complete a single measurement, therefore it may be up to two minutes before data is visible Check the integrity of the wiring. It could be poorly terminated cable. Check the polarity of the wiring. It is very easy to get the "A" and "B" the wrong way around Check for data on the RS485 bus. Ideally use a serial port on a computer to check for traffic. The baud rate is 9,600 bps. You should a string of numbers being transmitted periodically Check for data on the RS485 bus. Alternatively connect a volt-meter with a rapid response across the A and B links. a brief spike in voltage should be observed when data is present on the bus, Bear in mind the low update rate, and that the RS485 message only lasts a few milliseconds. |
MAIN SCREEN
REALTIME DIGITAL
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