News Flash
Indicator and CC-Link
Today's indicator has a great variety of communication with a programmable logic controller (PLC).
Now, let's look at the advantages of CC-Link (Control & Communication Link) which enables high-speed communication with indicators. First of all, CC-Link will enable high-speed input/output response.The communication speed reaches 10Mbps maximum depending on the distance; for example,at 10Mbps, the total extension of cable should be within 100m.
The dependence on distance of communication speed is as follows
Communication speed | Total extension of cable |
156kbps | 1200m |
625kbps | 900m |
2.5Mbps | 400m |
5Mbps | 160m |
10Mbps | 100m |
Second of all, it will be possible to connect multiple indicators with a single PLC.
Above all, the greatest feature of CC-Link must be to enable a link between memory addresses of indicator and PLC.
This makes it possible to eliminate a bulk amount of PLC program.
For instance, in order to control Hopper gate in communication between indicators and RS232C, it needed a certain program that would extract character strings of weighing data output from indicators, convert them into numerical values, and then constantly perform comparing process to the values.
It means that a program irrelevant to controlling was necessary to be written.
Sometimes multiple comparing programs were required depending on conditions.
On the other hand, when using CC-Link, e.g. Full flow, Medium flow, Dribble flow, etc., the gate can be easily controlled with only a program to monitor changes of memory address of PLC linked to that of indicator.
The methods of controlling with indicators have been gradually simplified in this way.