Parker Hannifin G2 Communication Specifications, 7 RS232C Interfaces, Communication parameters

7RS232C Interfaces

7.3Communication Specifications

[Communication parameters]

	Communication method	Start-stop system, text communication
	Communication speed	9600 bps
	Stop bit	1 bit
	Data length	8 bits
	Parity	None
	Terminate	CR (both transmission and reception)
	Flow control	None
[Single channel and multi-channel]
		Single channel		Multi-channel
	Topology	Cross	Ring
	ID	Unnecessary	Host device 0
			Drivers 1 to 9
	Destination specification	Unnecessary	Add the destination ID at the beginning of the packets
			From the host device to drivers: n****CR (n: slave station ID)
			From drivers to the host device: 0n****CR (n: slave station ID)

[Transmission from the host device to drivers]

The number of characters to be transmitted should be 128 letters or less, including the slave station ID, recognition key, transmission character string, and CR.

Single channel

Multi-channel

	Recognition	Transmission character string	CR
	key
Slave	Recognition	Transmission character string	CR
station ID	key

[Response from drivers to the host device]

The number of response characters should be 128 letters or less, including 0, slave station ID, recognition key, transmission character string, and CR.

Single channel

Multi-channel

		Recognition	Response character string	CR
		key
0	Slave	Recognition	Response character string	CR
	station ID	key

[Recognition key]

The recognition key is a function provided so that the host device can recognize that a response is a reply to a specific transmission by the host device. A maximum of 15 “!” characters can be included in the recognition key part. If more than 15 are added, the remainder of the number divided by 16 is processed as the actual recognition key number.

When the host device transmits a message to a driver and attaches N recognition keys to the transmission character string, the driver will send a response message back in which it attaches N recognition keys to that transmission character string. If, for instance, the host device issues a transmission character string to a driver that does not generate an immediate response, the host device may issue the next transmission character string before the response is returned. In such cases, it becomes difficult for the host device to recognize to which transmission character string the response character string returned afterward is issued. In this case, by issuing transmission character strings with different recognition key numbers, it becomes possible to judge to which transmission character string a particular response corresponds, simply by obtaining the recognition key number as the response is received.

7-4