Back to Signal Conversion commands
CMD_CNVT_REQ_VALUES 
Command:              CMD_CNVT_REQ_VALUES
Destination:          SD_CNVT
Destination Channel:  Channel ID

Description

Clients use this command to request that the signal conversion utility convert one or more signals from the indicated channel according to a previously read configuration file. The requested signal values are sent to the client using FT_SIG messages periodically or when they change.

A list of up to 255 Signal names may be included in the request. The data present in the FT_SIG message contains indexes and values of the requested values.

Command data format

Number of Signals Request Flag Request value First Signal Name ... Last Signal Name Padding
1 byte 1 byte 2 bytes variable ... variable 0-3 bytes

Number of Signals
The number of signal names to follow.

Request Flag
Specifies when the following signals are to be reported.
1:   The following signals are to be reported every time they appear in the defined message.
2:   The following signals are to be reported every time they change values.
3:   The following signals are to be reported when a counter set to the Request Value is decremented to zero. The counter is decremented every time the defined message appears. The counter is reset to its original value when it reaches zero. Ex. if the counter is set to ten, a new signal message will be sent every tenth message that contains the desired signal. Individual counters are maintained for each message.
4:   The following signals are to be blocked from being reported for the number of milliseconds present in Request Value. The result is that the signals are reported approximately once per the specified period.

Request Value
Parameter used for some Request Flag values. (Network byte order.)

Signal Name
The Signal Names are null terminated strings.


Response data format
 
Signal Request Index Number of Units First Signal's Units ... Last Signal's Units padding
1 byte 1 byte variable ... variable 0-3 bytes

Signal Request Index
Signal messages (FT_SIG) passed to client programs will have the Request Index element of the message set to this value. Values range from 0 through 255 and are unique for a given client connection.

Number of Units
The number of signal units that follow. This is equal to the number of signals in the request.

Signal's Units (First through Last)
A null terminated string. If there are no units for a signal, the teminating null is still present. The units are in the same sequence as the signals in the request.



Response return codes
RESP_OK Execution of the command was successful.
RESP_INVAL_CHAN The specified channel is invalid.
RESP_UNSUPPORTED This command is not supported on the specified channel.
RESP_UNREG The specified source channel is not registered with the server.
RESP_UNKNOWN_ERR An unknown error occurred.
|Top|