Quatech INTERBUS S manual Description of RS, Data Word Signal

Description of RS 232:

The interface module is designed to operate with all WAGO I/O fieldbus couplers. The serial interface module allows the connection of RS 232-Interface devices to the WAGO I/O SYSTEM. The RS 232 Interface module can provide gateways within the fieldbus protocol. This allows serial equipment such as printers, barcode readers, and links to local operator interfaces to communicate directly by the fieldbus protocol with the PLC or PC Master.

This module supports no higher level of protocol. Communication is made completely transparent to the fieldbus allowing flexibility in further applications of the serial interface module. The communication protocols are configured at the Master PLC or PC.

The 128 byte input buffer provides for high rates of data transmission. When using lower rates of transmission speed you can collect the received data, with less priority, without loosing data.

The 16 byte output buffer provides for faster transmission of larger data strings.

FUNCTION The data transmission takes place at 9.600 baud (default value). 1 startbit, 8 databits and 1 stopbit will be transmitted. No parity is available. The user controls data via the RTS and CTS signals. These signals are generated in the module depending on the loading status of the buffers. These controls can be deactivated by means of an external jumper. RTS and CTS are to be connected.

For testing purposes the Windows 3.11 terminal emulation can be used. A cable with a 9- pole sub-D socket is required. Pin 5 is connected to input M. Pin 2 is connected to TxD and Pin 3 to RxD. RTS and CTS of the module are connected. A hardwarehandshake between terminal emulation and SPS is not possible though.

Figure 2: Data Word Signal

RS232,TTY,RS485￿￿￿￿￿￿￿￿ 750-650,651,653 3

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