Chapter 9 Data Link

9-1 Description for data link function

·The data link function us used to send and receive ON/OFF signals (relay link: max. 2048 points) and

numerical data (register link : max. 2048 bytes) by PCs or between PC and personal computers connected in the satellite net system.

·The master station and slave stations are connected using a single coaxial cable. As the JW-20CM network module can control the data communications, the PC does not need any special programming.

·When the JW-20CM is assigned as a slave station, it has the standard function and memory capacity save function for data link. But the data contents for receiving from other stations is different between these two functions. (When the JW-20CM is used as a master station, only the standard function is available.)

[When all of a master station and slave stations are JW-20CM]

• Master station

 

 

 

Data link (Standard function)

Receiving data are all relay link area, and

 

 

 

 

 

 

 

 

 

 

 

• Slave station

 

 

 

Data link (Standard function)

all register link area of all stations.

 

 

 

 

 

Data link

 

 

In order to effectively use the memory,

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Memory capacity save function)

unify a partial data area or sending/

 

 

 

 

 

 

 

 

receiving address (program) of slave

 

 

 

 

 

 

 

 

stations.

·A maximum of 6 modules (a mixed installation of master and slave stations is allowed) can be installed on one PC.

·A maximum of 64 stations can transfer data on one network with maximum cable length of 1 km.

 

 

Personal computer

 

9

Master station 00(8)

Slave station 01(8)

slave station 02(8)

Slave station 77(8)

Network module

Network module

 

 

Network module

(JW-20CM)

(JW-20CM)

 

 

(ZW-20CM)

PC

PC

 

Network module

PC

 

 

 

 

 

 

 

(64 stations max., Total extension length: 1km max.)

 

 

Slave station 01(8)

Slave station 02(8)

Slave station 76(8)

Slave station 77(8)

 

Network module

Network module

Network module

Network module

 

(JW-20CM)

JW20

(JW-22CM)

(ZW-20CM)

(JW-20CM)

 

 

JW20H

 

 

 

 

 

JW30H

 

 

 

(64 stations max., Total extension length: 1km max.)

· Both JW and ZW model PCs can be connected on the same cable.

9·1