Products > BMS Analogue 4-20mA

The 4-20mA Analogue output feed is an optional module for the System5 Base or System5 BasePlus unit.

The function of the BMS unit is to provide external outputs for alarms or other measurement devices. Each BMS module has two analogue (4-20mA) outputs and two digital (switched relay) outputs.

PC Software (the IceSpy System5 ‘Adjust’ application) is able to associate these outputs with specific sensors which are being stored in the Base, or (for digital outputs) with specific logical zones that sensors may be allocated to.

Analogue Outputs

The analogue output is proportional to the value returned by the associated sensor. The minimum and maximum value is calculated as follows:-

Output of each channel is 20mA (i.e. high) if the current (latest) recorded value for that sensor is equal to or higher than the ‘MaxAxis’ value for that sensor.
Output of each channel is 4mA (i.e. low) if the current (latest) recorded value for that sensor is equal to or lower than the ‘MinAxis’ value for that sensor.
Note that these outputs are related to Max and Min possible range values, and not to alarm values for a sensor.
Associated sensors, and Max and Min settings are set up via the PC ‘System5 Adjust’.

Digital Outputs

If no specific sensors have been associated with the outputs using System5 'Adjust' , the state of the outputs depends on the alarm state of any of the sensors in any Zones which are set for BMS alarms. One channel output wil be normally closed, and one normally open. The channels will swap states in the event of an alarm condition.
For an associated sensor, the output of each channel is ‘closed’ if the sensor is in an alarm condition and open if not in alarm.
An alarm condition is defined by current value for that sensor being higher than the ‘High Alarm’ value for that sensor, or lower than the 'Low Alarm' value, and been so for longer than the ‘Alarm Delay Time’ for that sensor.
Zones, associated sensors, alarm levels and alarm delays are set up via the PC ‘System5 Adjust’.