Operational synchronous

When more than one JW-20CM is installed while using the remote I/O function, set only one module as “operational synchronous.” When a link module ZW-10CM or JW-10CM is used for remote I/O, the JW-20CM should be set as “operational asynchronous.”

a.When operation interval (one scan) of the master station PC is longer than data transfer time of the remote I/O:

I/O processing

 

 

 

 

Data exchange with the buffer memory

 

 

 

 

 

 

at PC side

 

 

 

 

I/O processing at PC side

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PC scan cycle

 

 

 

 

PC operation time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Remote I/O data

 

 

Remote I/O data

 

 

 

 

 

transfer processing

 

 

transfer processing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

b.When operation interval (one scan) of the master station PC is shorter than data transfer time of the remote I/O:

I/O processing at PC side

PC scan cycle

Data exchange with the buffer memory I/O processing at PC side

PC operation time

Waiting time

Remote I/O data transfer processing

8

A waiting time is provided after the PC process to match with end timing of the data transfer process of the remote I/O so that the remote I/O can synchronize with the PC scan cycle.

Operational asynchronous

The special I/O module can not be used with the remote I/O slave module as the special I/O module cannot synchronize with the master station PC for data exchange.

a.When operation interval (one scan) of the master station PC is longer than data transfer time of the remote I/O:

Same as operational synchronous above.

b.When operation interval (one scan) of the master station PC is shorter than data transfer time of the remote I/O:

I/O processing

 

 

 

 

 

Data exchange with the buffer memory

 

 

 

 

 

 

 

at PC side

 

 

 

 

 

I/O processing at PC side

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PC scan cycle

 

 

 

 

PC operation time

 

 

PC operation time

 

 

 

 

PC operation time

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Remote I/O data transfer processing

 

Remote I/O data transfer processing

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8·5