Sharp JW-20FL5, JW-20FLT, JW-50FL, Z-336J manual 96

Chapter 9: Message transfers

[2] Basic format of computer link commands

(1)Communication format

When a computer link is used, data sent from this node to a target node is referred to as a [com- mand], and data received from the target node by this node is referred to as a [response]. The communication format for commands and responses is as follows.

ËCommand

+2000	+2047	+2050	+2051	+2052	+2053
Header (40 bytes)		c-ID	ATTR	COM	Command Text

ËResponse

+0000		+0047	+0050	+0051	+0052	+0053	+0054
	Header (40 bytes)		r-ID	ATTR	COM	RSLT	Response Text
Header		: Normally, all 40 bytes are 00(H).
		If you want to communicate with Ethernet over two layers, you have to use an exten-
		sion header.
		(See "[5] Two-layer communication with Ethernet")
c-ID		: 47(H)
r-ID		: 45(H)
ATTR		: 00(H)
COM		: Command code (See page 9-14)
RSLT		: Command execution result
		Normally terminated with 00(H)
		If any byte other than 00(H) is found, an error code will be output (See "[4] Computer
		link error code table").
		If an error code is output, there is no response text.

Command Text : Command details (See "[3] Descriptions of each command")

Response Text : Response details (See "[3] Descriptions of each command")

[Example] When you want to monitor the ON/OFF status of relay 04033 See page 9-17. 9

ËCommand

Header (40 bytes) c-ID ATTR COM Command Text

	00		…	00	47	00	20	00	03		01			03
										File address					Bit 3
									000403(8) = 0103(H)
								File 0
									Relay No. 04033
Ë Response
		Header (40 bytes)			r-ID	ATTR	COM	RSLT					Response Text
	00		…	00	45	00	20	00	00		03			01		03		01
												File address					Bit 3		ON
									File 0		000403(8) = 0103(H)
Remarks
												Relay No. 04033

The maximum data length for read/write operations is 1024 bytes. In case of two-layer communication with the Ethernet, however, the maximum length is 256 bytes. For the UDP, the total number of bytes from the header to the command text must be less than 1024 bytes.

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