What is CCR control?
How the ALCMS tells a constant current regulator to switch and change brightness, how the CCR decides whether to obey, and how the result is reported back.
CCR control is how the ALCMS or a control panel operates a constant current regulator. The ALCMS sends a command, typically on, off or a brightness step, over a hardwired or network link to the CCR controller. The controller decides whether to act, and the CCR output then supplies the series circuit with the current for the selected step.
Two points matter in use. First, the CCR does not blindly obey: it acts only if its selector is set to remote and interlocks and protection allow it. A CCR in local ignores remote commands. Second, the feedback (state, step, output current and faults) is how the operator confirms the result. A remote command is a control action, not isolation. The circuit still has to be isolated, locked out and proved dead before work.
- Command. The operator selects on, off or a brightness step on the ALCMS screen.
- Link. The command is carried to the CCR over a hardwired or network connection.
- Decision. The CCR controller acts only if the selector is on remote and interlocks and protection allow it.
- Output. The CCR sets the series circuit current to match the selected step.
- Feedback. State, step, output current and any fault return to the ALCMS.
- Confirm. The operator checks that the feedback matches the command before relying on it.
CCR control from the ALCMS side: the commands sent, the decision at the CCR and the feedback returned.
The regulator itself: controller, steps and local and remote control. See CCR control architecture.
Frequently Asked Questions
Q1What is CCR control?
The way the ALCMS or a control panel switches a constant current regulator on and off and selects its brightness step, and reads back its state. The CCR controller receives the command, decides whether to act, and sets the output current for the selected step.
Q2What can the ALCMS command on a CCR?
Typically on and off, and the brightness step. Some systems also pass other commands, such as a fault reset, where the CCR and the project support them. What is available is set by the project specification and the CCR manufacturer.
Q3Does the CCR always obey a remote command?
No. The CCR controller acts only if the command is allowed. In most designs the local, off and remote selector must be set to remote, and protection or interlock conditions must permit it. A CCR in local ignores remote commands.
Q4What does the CCR report back?
Typically whether it is on or off, the selected brightness step, the output current, the local or remote state and any fault or alarm. This feedback lets the operator confirm that the circuit is doing what was asked, rather than assuming it.
Q5Is a remote off command the same as isolating the circuit?
No. A remote command is a control action, not isolation. Before anyone works on the CCR or its series circuit it must be isolated, locked out and proved dead under the permit-to-work, even if the screen shows the circuit off.
Q6How is CCR control different from the CCR entries in the CCR and Power Supply division?
Those entries describe the regulator itself, such as its controller, local and remote control and brightness steps. This entry looks at it from the ALCMS side: the commands sent, the decision at the CCR and the feedback returned.
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