What is the ALCMS-to-CCR link?
How the control system switches and dims a regulator — commands go down, and the CCR’s true state comes back to confirm them.
The ALCMS-to-CCR link connects the airfield lighting control and monitoring system to each constant current regulator. Commands — on, off and the brightness step — go to the CCR, which sets the matching current for its series circuit. Status comes back: whether it is running, which step, the output current, its local or remote mode, and any faults.
The link can be hardwired, with one wire per command and status, or a serial or network connection carrying them all. Either way the ALCMS does not just assume a command worked: it compares the feedback with what it asked for, and a mismatch is shown as a fault. Because the CCR only follows the ALCMS in remote mode, the mode must be reported too.
- Send. The operator selects a step and the ALCMS sends the command to the CCR.
- Act. The CCR, in remote mode, sets the corresponding output current.
- Report. The CCR returns its state, step, current, mode and faults.
- Confirm. The ALCMS compares the report with the command and flags any difference.
Frequently Asked Questions
Q1What is the ALCMS-to-CCR link?
The connection between the airfield lighting control and monitoring system and each constant current regulator. Commands such as on, off and intensity step go to the CCR, and its state, current, mode and faults come back.
Q2What commands does the ALCMS send?
Mainly switch on, switch off and select the brightness step. The CCR then sets the matching output current for its series circuit.
Q3What status comes back from the CCR?
Typically whether it is on or off, the step it is running, the output current, whether it is in local or remote mode, and any fault or alarm indications.
Q4How is the link made?
Either by hardwired contacts, where each command and status is a separate wire, or by a serial or network communication link carrying many items over one connection. The choice depends on the equipment and the project design.
Q5Why does the CCR mode matter?
The CCR only follows the ALCMS when its selector is in remote. In local or off, commands from the control system do not take effect, so the ALCMS needs to show the mode as well as the step.
Q6How does the ALCMS know a command worked?
By feedback. The CCR reports its actual state and current, and the ALCMS compares this with what was commanded. A mismatch is shown as a fault rather than being assumed to have worked.
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