Manual Weighing Controller A 810
Page
76
A.S.T. Angewandte SYSTEM-TECHNIK GmbH Dresden
4.2.4. Physical Protocol (Handshake)
The physical protocol is for avoiding the loss of data. Each receiving device allows the transmission of
characters only when it is able to receive them. When A810 receives a signal 'disable transmission', its
transmitter channel will just complete the character currently transmitted. The receiver channel is able to
receive another 20 characters after the 'disable transmission' signal has been transmitted to a peripheral
device before any loss of data will occur. Each serial interface may operate either without handshake or
observing the software protocol. When the software protocol is used, transmission is enabled by the
transmitter receiving the XON character (DC1, code 11h) and transmission is disabled by the XOFF
character (DC3, code 13h).
4.2.5. Logical Devices
During commissioning, each logical device is allocated a serial interface. Logical devices are printer,
remote display unit, PC / SPC, second operating unit and measuring BUS. If there are two logical
printers, so two printers can in fact be connected to one terminal.
4.3. Printers
The type A810 terminal is able to communicate with different printers. The type of printer has to be set
during commissioning. Traffic between a terminal and a printer depends on the selected mode. This
applies to the transmission of certain print commands (Escape sequences). The following printers are
supported by a A810 terminal and can be set during commissioning:
•
CR/LF
printer
Any printer can be used as a CR/LF printer provided it can process a 7-bit or 8-bit code and control
characters Carriage Return (CR, code 0Dh) and Line Feed (LF, code 0Ah). The terminal will not
transmit any Escape sequence to a CR/LF printer. Thus no part of the text can be highlighted.
•
TM295
The A810 supports the following specific control characters: Line Feed forward/backward, Form
Feed forward/backward, Capital Letters on/off, Switch to German Character Set, Lift Pinch Roller.
•
Epson printers of series LX, FX, LQ
The following Standard Escape Sequences are supported which are suitable for other software
compatible printers, too: Carriage Return, Line Feed, Form Feed, Wide Font on/off, Bold Font
on/off, Narrow Font on/off, Italics on/off, Underline on/off.
•
STAR printer SP212, SP312, SP349
The following control characters are supported: Carriage Return, Line Feed, Wide Font on/off, Set
to German Character Set, Cut Paper.
Please note that the standard program does not support any teleprinter since there is no reason for a
terminal with EU approval to be connected to a teleprinter.
4.4. Remote Display Units
4.4.1. A810 Remote Display Units
Any system compatible remote control and display unit of the A810 will not be used as logical device
'Remote display unit' but instead as logical device 'Second operating unit'. This simplifies the
configuration of the interface and enables more functions to be used, e.g. for the commissioning program.
