Data Communication

Data communication is a function enables you to communicate data with external devices in PacScript.

Task and Line

In Data communication, task opens a line and data communication will be performed through the line.

Once a task opens the line, the task acquires a communication permission of the line and the line cannot be opened by the other tasks. Task can open multiple lines, but a line cannot be opened by the multiple tasks concurrently. The line which has already opened cannot be accessed by the other tasks.*

Regardless of task status or running mode, the controller retains the information about line number and which task opens until the power supply turns OFF.

Selection of Communication Method

You can select from two types of communication methods Ethernet or RS-232C for data communication.

The communication method should be assigned according to the line number.

RS-232C

In RS-232C communication, handshake is not performed, so the line should be opened surely using Comm.Open.

When the line is opened, transmitted data will be stored in the communication buffer. Acquire the stored data using Comm.Input.

Line numbers of RS-232C are 1, 2, 3, 40 and 41.

Correspondence between a line number and a physical port can be designated in "Communication port setting". Refer to setting screen.

Ethernet

Line numbers of Ethernet are 4 to 15.

Ethernet data communication sends/receives data after surely establishing the line connection.

In Ethernet data communication, the communication will be established by "client" line connection to "server" line. "Server" and "Client" communication will be established in one-to-one basis.

Process of establishing Ethernet line communication is as follows.

1. Open the server side line.
2. Open the client side line. An error message will be displayed when the server line is not opened.
3. Send/receive data.

Selection of Data Type

You can select the following two types of data for communication.

Text

Send/receive text data.

Binary

Send/receive binary data. Refer to "data communication in binary mode."

Commands Used in Data Communication

You can use the following commands for data communication.

Command name	Function
Comm.Open	Open the line for data communication.
Comm.Close	Close the specified line for data communication.
Comm.Output	Send data through data communication function.
Comm.Input	Receive data through data communication function.
Comm.Clear	Clear the receive buffer of data communication.
Comm.Count	Return the number of bytes for data which can be read from receive buffer of data communication function.
Comm.State	Return port status of data communication function.