Teledyne 100AH instruction manual Protocol of Port Communication, Key Function

Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D

The RS-232 LOGON feature must be enabled from the front panel by setting bit 4. See Table 7-1.Once the feature is enabled, to logon type:

LOGON 940331

940331 is the default password. The password can be changed to any number from 0 to 999999 by the variable RS232_PASS. To change the password enter the command

V RS232_PASS=xxxxxx

which sets the password to the value xxxxxx.

7.1.3 Protocol of Port Communication

The RS-232 interface has two protocols of communication, because if the port is attached to a computer it needs to have different characteristics than if used interactively. Consequently, there are two primary styles of operation: terminal mode and computer mode.

When an operator is communicating with the analyzer via a terminal, the analyzer should be placed into TERMINAL MODE, which echoes keystrokes, allows editing of the command line using the backspace and escape keys, and allows recall of the previous command. When a host computer or data logger is connected to the analyzer, it should be placed into COMPUTER MODE, which does not echo characters received or allow the special editing keys.

Table 7-2: RS-232 Switching From Terminal Mode to Computer Mode

Key	Function
Control-T (ASCII 20 decimal)	Switch to terminal mode (echo, edit)
Control-C (ASCII 3 decimal)	Switch to computer mode (no echo, no edit)

If the command line doesn't seem to respond to keystrokes or commands, one of the first things you should do is send a Control-T to switch the command line interface into terminal mode. Also, some communication programs remove CTRL-T and CTRL-C characters from the byte stream, therefore these characters will not be sent to the analyzer. Check your communications program owners manual.

7-3