Omron CJ1W-DRM21 Scan List Enabled and Scan List Disabled, Creating the Scan List, Shown below

Scan List			Section 4-2
Creating the Scan List	The way that a scan list is prepared varies with the allocation method as
	shown below.
	Fixed allocations	User-set allocations	User-set allocations
		through the allocated DM	through the Configurator
		Area words area
	With the CPU Unit in PRO-	With the CPU Unit in PRO-	Create a list from the Con-
	GRAM mode:	GRAM mode, turn ON the	figurator. (Acquire a list of
	1. Turn ON the one of the	Master User Allocations	online devices, use it to
		Setup Switch.	create a scan list, and then
	Master Fixed Allocation
	Setting 1 Switches (1 to		register the scan list in the
			Master Unit.)
	3).
	2. Turn ON the Scan List
	Enable Switch.

Note 1. Be sure to create a scan list before starting actual system operation.

2.It is still possible to communicate with Units (with the scan list disabled) if a scan list is not created when fixed allocations areas 1 to 3 are used. This may result in faulty operation because the Master Unit will communicate with slaves even if they do not start up due to problems, such as equipment failure if there is no a scan list.

Scan List Enabled and Scan List Disabled

The scan list must be made. The scan list modes are described here.

Scan List Enabled (Used Remote I/O communications are performed according to the registered scan

for Actual Operation) list and only with slaves that are on the list. A verification error occurs (word n+12, bit 00 in the status area turns ON) if a slave registered on the scan list is not present on the network, if a slave did not start up when remote I/O com- munications started, or if the number of I/O points did not match the number registered.

Scan List Disabled (Used Remote I/O communications can be performed with fixed allocations instead

when Changing System of a scan list in order to change a system component. Do not operate without

Components)a scan list during actual system operation. Use this mode only to replace a Master Unit or to change a system component (change a connected slave or a node address).

Note a) To disable the scan list, turn ON the Scan List Clear Switch (word n, bit 01) during remote I/O communications with the scan list en- abled (with fixed allocations, user-set allocations using allocated DM Area words, or user-set allocations using the Configurator). In all these cases, remote I/O communications are executed using the fixed allocations area that was last used when the list was dis- abled. All slaves are targeted for remote I/O communications with the scan list disabled.

b)Slaves that are connected to the network while communications are in progress are also targeted for communications. Errors can- not be confirmed, however, even if there are slaves present that did start up due to problems such as equipment failure because there is no scan list available to check communications against. The communications cycle time will also be significantly longer than the calculated value.

c)The scan list is automatically enabled when user-set allocations are set using the allocated DM Area words or the Configurator. If the list is subsequently cleared using a software switch, fixed allo- cations (1 to 3) will be used for remote I/O communications when the scan list is disabled. Make sure the system has stopped before

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