Input Voltage Alarm Limits
(Note: Four analog outputs available on specific
The RT series RTU’s is capable of monitoring its input voltage. This section will describe how to set and enable the “Input Voltage Alarm Limits”.
If the “Alarm On Input Voltage Limit Error” is enabled and the INPUT supply voltage rises above the “High Limit” or falls below the “Low Limit” the respective RTU will sound an alarm.
The alarm will stop sounding when the input supply voltage returns to ”normal” by returning between the +/- limits determined by the “High/Low Limit Dead Band”. The “Normal” +/- limits are calculated by subtracting the “High/Low Limit Dead Band” from the “High limit” and adding the “High/Low Limit Dead Band” to the “Low Limit”
The configuration shown above will cause a HIGH alarm if the input supply voltage rises above 28.0 VDC and will return to normal when the input supply voltage falls to 26.01 VDC.
The configuration above will cause a LOW alarm if the input supply voltage falls below 9.99 VDC and will return to normal when the input supply voltage rises to 11.98 VDC.
Manual Documentation Number: | 41 |
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph
Analog Outputs Resting Voltage
(Note: Four analog outputs available on specific
This section applies to Peer to Peer and Modbus systems. In peer to peer mode, the master and slave communicate with each other and during the communication process they share information. In the event of a communication failure, the updating process will stop and if the Communications alarm is disabled the analog outputs for the master and slave will be the last valid update.
A communications error will occur if the number of consecutive failed polling attempts exceeds the programmed number of retries. This count is reset if even one valid communications update occurs before the number of retries expires and if the RTU is a Modbus device, a communications of 2 minutes must laps.
The analog output resting voltages provide a means to program the voltage outputs in the event of a communications error.
Due to the nature of wireless systems, communication failures may occur. The RT series RTU’s allow you to program each of the analog outputs with a preset level in the event of a communications failure. Each analog output can be programmed with independent levels from 0 volts to 5 Vdc.
If the RTU is programmed to respond to a communications alarm and a communications failure occurs, the respective RTU will force the outputs with your preset levels. The outputs will return to normal once communications is reestablished.
To program the RTU to respond to communications failures select the “Set Rest Voltage on Comm Error” and update the configuration by pressing the “Send Changes To Device”.
42 | Manual Documentation Number: |
B&B Electronics Mfg Co Inc – 707 Dayton Rd - PO Box 1040 - Ottawa IL 61350 - Ph
