Maintenance
The relay is controlled by the temperature selected on the display. If any failsafe code appears on the display, the relay changes to the “abnormal” state. The exception is the “dirty window” condition. This causes the relay to change state, leaving a normal numerical temperature output. The dirty window is detected in either 1‐color or 2‐color mode.
| Error Code | 0 – 20 mA Output |
| 4 – 20 mA Output |
|
| no error | according to temperature |
| according to temperature |
|
| ECHH | 21 to 24 mA | 21 to 24 mA |
| |
| ECUU | 0 mA | 2 to 3 mA |
| |
| EIHH | 21 to 24 mA | 21 to 24 mA |
| |
| EIUU | 0 mA | 2 to 3 mA |
| |
| EUUU | 0 mA | 2 to 3 mA |
| |
| EHHH | 21 to 24 mA | 21 to 24 mA |
| |
| EAAA | 0 mA |
| 2 to 3 mA |
|
Table 11: Current Output Values in accordance to an Error
If two errors occur simultaneously, the higher priority error is the one that is presented on the LED’s digital and analog outputs. For example, in 2‐color mode, if the internal ambient is too high and the attenuation is too high, the unit outputs EIHH on the LED’s and digital output and 21 mA on the analog output. However, since 2‐color wide band and narrow band temperatures may all be presented simultaneously through RS485, their over and under range conditions are independent.
Examples of failsafe conditions:
1.One‐color temperature is selected for display on the LED’s. Two‐color temperature is transmitted in burst mode. Wide band temperature is under range. Two‐color temperature is 999°C.
Outputs:
Display:
RS485:
Analog:
Relay:
2. Two‐color temperature is selected for display on LED’s. All three temperatures are transmitted in burst mode. Two‐color temperature is 1021°C. Wide band temperature is 703°C. Narrow band temperature is 685°C. Attenuation is above 95%, the “dirty window”
threshold. |
|
Outputs: |
|
Display: | 1021 |
RS485: | C T1021 W0703 N0685 |
Analog: | scaled to temperature, between 4 and 20 mA |
Relay: | abnormal state |
Marathon Series FA/FR | 47 |