Omron CJ1W-DRM21, CS1W-DRM21 operation manual Precautions on the Number of Master Units

Master Remote I/O Communications										Section 4-1
Item								Specifications
Max. No. of I/O	Fixed allocations				2,048 pts (64 input words, 64 output words)
per Slave con-
	User-set		By allocated		3,200 pts (100 input words, 100 output words)
trollable by a
	allocations		DM Area
DeviceNet Unit
			words
			By Configu-	3,200 pts (100 input words, 100 output words)
			rator
4-1-3 Precautions on the Number of Master Units
			The following system configurations can be constructed based on various
			numbers of Master Units when DeviceNet Units are used.
Pattern		One Master Unit				Multiple Master Units connected				Multiple Master Units connected
		connected on a single					on a single network			to a single PC
			network
Configuration
						Yes
						A			B

Remote I/O communications
	Fixed alloca-		❍	⋅	❍ (Up to 3 Master Units can be
	tions				used.)
	User-	By DM	❍	❍ (See note.)	❍
	set	Area
	alloca-	words
	tions
		By	❍	❍ (See note.)	❍
		Config-
		urator
Precautions			Same as previous net-	• The communications cycle time	• The cycle time of the PC is long-
			works.	is longer.	er.
				Note The communications cycle	• Make sure that each word allo-
				time for the network in the	cated in the system is allocated
				figure above is TA+TB if	to only one Master Unit.
				sections A and B above are
				separate networks with a
				communications cycle time
				of TA and TB.
				• Multiple Master Units cannot
				share a single Slave Unit.
				• Bus Off errors (communications
				stopped by multiple transmis-
				sions) may occur if multiple
				Master Units with disabled scan
				lists are present on a single net-
				work.

Note Only one Master Unit can be connected to a network if the user specifies a COS or cyclic connection from the Configurator. Remote I/O communications errors may occur is more than one Master Unit is connected for a COS or cyclic connection.

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