Detcon 700 Remote Sensor/Alarm Relay Module - Manual (Page 11)

700 RAM I.M.
3. Set-up and Normal Operation
In normal operation, the RAM display continuously shows the current sensor reading, which will typically
appear as “ 0 ”. Once every 1 minute the LED display will flash the sensor’s measurement units and gas type
(i.e. % LEL). If the 700 Gas Sensor or RAM is actively experiencing any diagnostic faults, a “Fault
Detected” message will flash on the display once every minute. When the unit is in “Fault Detected” mode
with the red Fault LED on, PGM1 or PGM2 can be swiped to invoke a display of the active faults.
In normal operation, the 4-20mA current output from the RAM corresponds with the present gas
concentration and full-scale range. The RS-485 Modbus™ serial output provides the current gas reading and
fault status on a continuous basis when polled.
Successful Modbus™ communications between the RAM and the RS-485 Master Controller will be
indicated by a blinking “CAL” LED. If the Modbus™ communication between the RAM and the 700 Gas
Sensor is not functioning the RAM will display “COMM” and the “FLT” LED will be illuminated.
NOTE: The 700 Gas Sensor must be set to Serial ID = 01 for proper communications set-up
with the RAM.
3.1 View Sensor Status
View Sensor Status displays all current configurational and operational parameters from the 700 Gas Sensor
attached to it. These typically include sensor type, software version number, detection range, AutoSpan
level, days since last AutoSpan, estimated remaining sensor life, sensor diagnostics, input voltage, 4-20mA
output, and sensor ambient temperature.
To access the View Sensor Status menu, hold the magnet over PGM2 (ª) until the arrow prompt appears
and then hold continuously for 3 seconds. This will display the View Sensor Status text scroll. From the
“View Sensor Status” text scroll, hold the magnet over PGM1 (©) or PGM2 (ª) until the arrow prompt
appears and then hold continuously for an additional 3 seconds. The display will scroll the complete list of
sensor status parameters sequentially:
Current Software Version (of the RAM)
Sensor Model Type
Range of Detection
Serial ID address
AutoSpan Level
Days Since Last AutoSpan
Remaining Sensor Life
Sensor Diagnostics (varies by sensor type)
4-20mA Output
Input Voltage Supply
Sensor Temperature
Alarm 1 Settings
Alarm 2 Settings
Fault Settings
When the sensor status list sequence is complete, the RAM will revert to the “View Sensor Status” text
scroll. The user can then choose to either: 1) review list again by executing another 3 second hold, 2) move
to another menu item by executing a momentary hold, or 3) return to Normal Operation via 15 second
automatic timeout.
700 RAM I.M. Rev. 1.0 Page 7 of 13