Fluke RPM4 manual Classic Program Message Format, Enhanced Program Message Format

4. REMOTE OPERATION

4.3.1 CLASSIC PROGRAM MESSAGE FORMAT

Each program message sent is also a query. You can only send one program message to the RPM4 at time. After sending any program message, you must wait for the RPM4 to reply before sending another program message. This reply will contain data, or a numeric error message if the program message was invalid. You must wait for this reply before issuing another program message to the RPM4. This insures that the RPM4 has completed the program message. Most remote program messages will return a reply within 500 ms except:

“PR?”, “PRR?”, “SR?”, “ATM?”, “RATE?”: Up to 2 seconds. “RPT”, “ARANGE”, “AUTOZERO=RUN”: Up to 3 seconds

The syntax and format used for each program message in the classic mode is listed next to the keyword “Classic”’ in each program message summary in Section 4.4.4.

4.3.2 ENHANCED PROGRAM MESSAGE FORMAT

The enhanced program message format uses the IEEE Std. 488.2 format, syntax and status reporting. Errors are reported using the IEEE Std. 488.2 status reporting model. If an error is reported, the error is put into an Error Queue and the “ERR?” query program message can be used to get a text description of the most recent error. If you are using the IEEE-488 port, the service request line can be setup to be asserted if this occurs (see Section 4.5.2). In the enhanced format, there are two possible program message types for every program message. Each of these two types starts with the same basic text referred to as the program message header. The two types are COMMAND type and QUERY type commands.

4.3.2.1USING COMMAND TYPE COMMANDS

Enhanced format commands DO NOT reply when using the IEEE-488 interface unless a “?” is included in the command. Do not expect a response from the RPM4’s IEEE-488 interface to non-query (no “?”) commands as there is none. Remote software will time-out waiting for a response from RPM4. However, in RS232 communications, there is always a response and the response MUST be read prior to issuing another command.

The COMMAND type of program message executes a process and can additionally send data to the RPM4 in the form of comma delimited arguments. This data is usually a setting of some sort that is stored in the RPM4. If data is specified, it must be preceded by at least one white space from the program message header and be within the range and format described in the program message description. The keyword “Command:” appears to the left of the required syntax in each program message description in Section 4.4.4.

If you are using the IEEE-488 port, the Command type does not generate a reply unless you place a query operator “?” immediately after the command. You also may send multiple program messages at once by separating each program message with a semicolon. The commands are queued and executed in as received order after the entire message stream has been received, so care in determining order of execution is needed.

If you are using the RS232 port COM1, the Command type will always generate a reply so you must wait for a reply before issuing another program message. Because of this, you can only send one Command program message at a time while using the COM1 port.

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