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Commands |
A Control Relay Output object (Object 12, Variation 1) defines the message fields, described on the next table.
Bit |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
Meaning |
Trip/Close |
Clear |
Queue |
Code |
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•Trip/Close: This field determines which control relay is activated in a system where a pair of trip and close relays is used to energize or de-energize points in the field. Possible values are, in binary format, 00: NUL, 01: Close, and 10: Trip. The NUL value can be used to activate trip or close relays. In a system without selection relays, the NUL value does not perform any operation. In a system without trip or close relays, on the other hand, this field must always be NUL to indicate a normal operation of digital control, where the exact point of control is implicit or fully known. This field does not support trip and close commands simultaneously, which is an illegal operation
•Clear: If the command contains this field set to 1 (one, turned on), all control operations are removed from the queue, including the command currently executed, and this control operation is performed
•Queue: Indicates that a command was placed on a queue in the device. If this field is equal to 0 (zero, NUL), then no operation is placed on the queue and that queue is cleared from all controls, including the command currently executing if the Clear field is turned on. When the control function is executed and completed, it is removed from the queue. If the command contains the Queue attribute turned on, then this operation is queued again, that is, placed at the end of the queue for that point
•Code: This field specifies the type of operation. This command can be used with devices that support queuing commands, point to point, or other control mechanisms. In the first type, any control command must be queued for the point. In the second type, each control is performed until completed before the next command be accepted for that point
Possible values for Code, in binary format
Value |
Operation |
Description |
|---|---|---|
0000 |
NUL |
No operation is performed |
0001 |
PULSE ON |
The point, or points, is turned on by the time specified in On Time, turned off by the time specified in Off Time, and left in the OFF status |
0010 |
PULSE OFF |
The point, or points, is turned off by the time specified in Off Time, turned on by the time specified in On Time, and left in the ON status |
0011 |
LATCH ON |
Keeps a point or points in the ON status |
0100 |
LATCH OFF |
Keeps a point or points in the OFF status |
NOTE |
Values outside the previous table are not defined. |
This byte indicates how many times an operation is executed. This value is kept fixed in 1 (one) by this Driver.
On-time, in milliseconds, defined on this Driver's extra configurations. This value is fixed for all commands.
Off-time, in milliseconds, defined on this Driver's extra configurations. This value is fixed for all commands.
Status of an operation returned by this Driver if that operation was successfully finished. This status is only interpreted on the response, and it can be used by an application to check whether a command was executed successfully. These codes are the following:
•0: Command executed correctly, including Select and Operate operations
•1: Operate command sent after the maximum time of a Select command defined by the Slave
•2: Operate command sent without a previous Select command
•3: Message with formatting errors
•4: Operation not supported for this point
•5: Queue is full or this point is already active
•6: Hardware problems
•Others: Non-standard error codes