Parker Hannifin GEM6K manual Ntwrit, What conditions can disable the Network Program Select Mode?

3.Start polling the PLC for integer data (NTPOLL). When the 6K polls the PLC, it will read the value of the mapped Element into the associated 6K integer variable (VARI).

4.Use the NTSELP command to enable the Network Program Select mode and identify the 6K integer variable (VARI) to supply the program selection number. Once enabled, the 6K will poll the PLC (at the NTPOLL rate), read the integer data from the PLC into the mapped VARI variable, and execute the program (by number) according to the value of the mapped VARI variable. After executing and completing the selected program, the controller will resume polling the inputs again. To disable the Network Program Select mode, place the NTSELPØ command in a program that can be selected.

5.Program the PLC to set the Element value to select the program (by its number) in the 6K. For example, suppose Element #4 of File #2 is mapped to the 6K’s integer variable #9. If the value of Element #4 is 8 when it is polled, the 6K will execute program #8.

WHAT IS THE PROGRAM NUMBER?

A program’s number is determined by the order in which the program was downloaded to the controller. The first program downloaded is program #1, the second downloaded is program #2, etc. The number of each program stored in the controller's memory can be obtained through the TDIR report — refer to the number reported in front of each program name. When selecting programs with an integer variable (mapped to an Element in the PLC data file), the 6K will execute the program number that matches the value of the variable at the time the associated Element was polled from the PLC.

Multi-Tasking: If you are using multi-tasking, be aware that each Task has its own Network Program Select Mode. If you wish to enable variable-initiated program selection in an external task (a task other than the task that is executing the NTSELP command), then you must prefix the NTSELP command to address the targeted task. For example 3%NTSELP1,40 enables Network Program Select Mode in Task #3, and uses the value of VARI40 to program the number of the program to execute.

What conditions can disable the Network Program Select Mode?

•Executing the Kill (!K) command

•Executing the Stop (!S) command, or activating an input defined as a stop input (see INFNC or LIMFNC). This disables Program Select Mode only if the Task is operating in the COMEXS2 mode.

Example:	; Network	server #2 is an Allen-Bradley PLC at IP address
2NTIP1,172,54,125,34
2NTCONN1	; 172.54.125.34
	; Attempt	connection to network server #2
2NTMPRI20,5,2,128	; VARI128	and VARI129 (in the 6K) are mapped to File 20, Elements
	; 5 and 6	in the AB PLC. The values of VARI128 and VARI129 will be
2NTPOLL50	; derived	from the values of File 20, elements 5 and 6 in the PLC.
	; Start polling		the AB PLC, set polling interval to 50 ms
3%NTSELP1,128	; VARI128	is the network program select variable, which is mapped
	; with File 20,		Element 5, in the AB PLC. When the 6K polls
	; Element	5, it	will execute the program according to the value
	; of Element 5.		The program will be executed in Task 3.

NTWRIT		Network Write ASCII String to DVT Camera
Type:	Network		Product	Rev
Syntax:	<!><n>NTWRIT"<message>"		6K	5.3
Units:	n = network server #
	message = ASCII string
Range:	n = 1-6
	message = up to 69 characters (cannot use ", ; or :)
Default:	n/a
Response:	n/a
See Also:	NTIP

Use the NTWRIT command to write ASCII strings to the DVT camera. If you address the NTWRIT command to a non-DVT connection (see NTIP), the 6K transmits the error message “INVALID SERVER TYPE”.

Example:

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