User Instructions

Selecting Trouble Fan Setting Option – “tFS”

To select the Trouble Fan Setting Option, in normal mode, push the Next button to get to “Con” or the Configuration menu. Then

push the Enter button to enter the Con menu. The eleventh selection is the “tFS” or Trouble Fan Setting Option. Push Next ten times

to get to “tFS” then Enter. If Trouble Fan Setting is “OFF” push Next to turn it to “ON” (flashing) then push Enter to confirm the change

(solid) and push Enter again to return to “tFS” in the Con menu. Push Next until “End” is displayed then push Enter to get back to

normal operation.

Selecting 4-20mA Output Option – “420”

To select the 4-20mA Output Option, in normal mode, push the Next button to get to “Con” or the Configuration menu. Then push the

Enter button to enter the Con menu. The twelfth selection is the “420” or 4-20mA Output Option. Push Next eleven times to get to

“420” then Enter. If the 4-20mA is “On” push Next to turn it to “OFF” (flashing) then push Enter to confirm the change (solid) and push

Enter again to return to “420” in the Con menu. Push Next until “End” is displayed then push Enter to get back to normal operation.

Onboard Diagnostics

The CM-6 monitors all critical functions of the unit through software diagnostics that continuously test and verify unit operations. If a

problem is found, the unit will switch to a fail-safe/error mode or trouble condition. In this error mode, the Alarm relay will be activated,

the 4-20 mA current loop will go to 24 mA, the unit will display the error code, the green status indicator LED light will flash and the

buzzer will chirp intermittently. The Fan relay will also engage if the Trouble Fan Setting Option is set to “ON”. This is a safety

precaution. To clear this mode, simply turn off power to the unit for a few seconds, or push the ENTER/TEST switch (inside the unit).

This will cause the unit to restart the 1 minute self-test cycle.

The 4-20 mA signal can be used for troubleshooting:

 0 mA is most likely a connection problem

 4-20 mA is normal gas reading range (0-200 ppm)

 24 mA indicates a Trouble condition

Error Codes

 t01 Sensor missing

 t02 Temperature compensation failure

 t04 EEPROM bad checksum

 t08 Sensor is shorted

 t10 Bad EEPROM

 t20 Bad calibration



t40 Factory calibration failure

 t80 Read ADC failure

 t100 Under range

 t200 Sensor expired

NOTE: For trouble codes over 080 the display will alternate between t_1 and t00 for t100 and between t_2 and t00 for t200.

If the error mode repeats frequently, check for continuous power and proper voltage. If power is not the problem and a unit has

repeating error conditions, it may need to be returned to Macurco for service, per these User Instructions.

If the error mode indicates “Sensor expired” see the Sensor Life Reset section of these User Instructions.