Parker Hannifin GEM6K manual Related Error Status register bits are noted below

Error Response	Possible Cause
NTSELP ALREADY ENABLED ON THIS	NTSELP, which enables program selection via OPTO22
TASK	inputs, has already been enabled (if multitasking, it has
	been enabled for this specific Task).
OPTION CARD CAN NOT BE USED WITH	Tried to enable the internal Fieldbus Option card for
ETHERNET - SEE NTFEN	PROFIBUS or DeviceNet communication (6Kn-PB and 6Kn-
	DN products only) with the OPTEN1 command. You must
	disable Ethernet communications with the NTFENØ
	command before enabling the Option card. The 6K cannot
	communicate over a Fieldbus connection and Ethernet
	connection simultaneously.
VARB USED BY OPTION CARD	Tried to map a binary variable to read from or write to an
	Allen-Bradley data file, but the variable is already used for
	Fieldbus (PROFIBUS or DeviceNet) data transfer functions.

VARIABLE MAPPING CONFLICT, SEE NTMPRB, NTMPRI, NTMPWI, NTMPWB MAPPINGS

Tried to map the same 6K VARB or VARI variables for read and write functions. Or tried to map the same 6K VARB or VARI variables to another PLC.

Error Handling	The 6K has a Error Status register for logging certain error conditions. If you enable checking
	for an error condition (see ERROR command), the 6K will branch to the designated error
	program (see ERRORP command) when it detects the error condition. The Ethernet networking
	related Error Status register bits are noted below.

ERROR	Cause of the Error	Branch Type	How to Remedy the Error
Bit #		to ERRORP
23	Ethernet Client	Gosub	Clear the error bit (ERROR.23-0), re-establish
	Connection Error.		the Ethernet connection (nNTCONN1), and
	(Can’t connect.)		then issue ERROR.23-1.
24	Ethernet Client Polling Error.	Gosub	Clear the error bit (ERROR.24-0), re-establish
	(After connect and polling		the Ethernet connection (nNTCONN1), and
	device for data, polling		then issue ERROR.24-1.

timeout occurred. Cause could be disconnect, client lost power, etc.)

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