Omron CS1W-CLK21-V1 Inactive Data Links, Calculation Example, Instruction When sent When received

Communications Cycle Time Section 8-2

E:Total number of bytes in messages transmitted during the communications cycle

The number of bytes in each message differs according to the instruction being issued.

Instruction	When sent	When received
SEND	Number of words to be sent ⋅ 2 +	14
	18
RECV	18	Number of words to be received
		⋅ 2 + 14
CMND	Number of bytes in command	Number of bytes in response
	data + 10	data

Calculation Example	Communications conditions are as follows:
	Transmission medium:		Twisted-pair cable
	Baud rate:		2 Mbps
	Network parameters:		Defaults
	Max node address:		32
	Polled nodes per comm cycle:		4
	Event-frames per comm cycle:		35
	Network configuration:		8 nodes
	Total number of data link words:		8,000 words
	Nodes that send messages:		2 nodes
	Bytes in all messages sent:		2,012 ⋅ 2 bytes
	In this example, A to E in the equation have the following values.
	A:	8,000
	B:	4
	C:	8
	D:	2
	E:	4,024

The communications cycle time is thus as follows:

10 ⋅ 8,000 + 600 ⋅ 4 + 290 ⋅ 8 + 320 ⋅ 2 + 4 ⋅ 4,024 + 3,290 = 104,746 (∝s)

≅105 (ms)

8-2-2 Inactive Data Links

The following equations are used to calculate a communications cycle time when the data link is inactive.

Wired Systems

Baud rate							Equation
2 Mbps	600 ⋅	B + 110 ⋅		C + 320 ⋅		D + 4 ⋅		E + 2,290 (∝s)
1 Mbps	1,150	⋅	B + 150	⋅	C + 360	⋅	D + 8	⋅	E + 2,690 (∝s)
500 Kbps	2,260	⋅	B + 230	⋅	C + 440	⋅	D + 16 ⋅		E + 3,490 (∝s)

Note B: Number of polled nodes per communications cycle

(value specified in the network parameter)

C:Number of nodes connected to network

D:Number of nodes that send messages during the communications cycle

E:Total number of bytes in messages transmitted during the communications cycle

252