SCS PTC-IIex, Manual

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6 Commands
The status word polling in the PTC-IIex is permanently turned on. The status command
has only been retained for compatibility reasons. Any argument is ignored.
This command facilitates polling of all operational states of the PTC via the serial
interface. This is useful for mailbox systems, or more luxurious terminal programs.
The status byte is called by the RS character (ASCII decimal 30). This definition of the
status request byte does not impose any restrictions on data transparency. PACTOR uses
ASCII 30 (decimal) as the
idle byte which can only be transmitted via a supervisor
sequence.
The PTC's status reply always begins with an echo of the RS character (ASCII decimal
30) to facilitate unique identification of the status information following. The actual status
byte follows this
header .
This modular status level concept facilitates an expansion of the status information in the
future, i.e., in a higher status level, even several bytes containing status information can
be implemented. The status bytes (incl. header) are sent in direct sequence.
During the transmission of status information new status requests are ignored.
The status information is processed totally independent from the current XON/XOFF
state of the serial interface.
In status mode 2, the PTC-IIex has an automatic status output. This means that the status
no longer needs to be regularly polled by the terminal program. Instead, every status
change causes the status information automatically to be given. The status output is in the
usual format: 30, S (S = status-byte). In status mode 2, the status byte can still be polled
via the terminal as before, for instance directly after the start of the terminal program.
Hints for programmers: Through the PACTOR software the status reply may be delayed
by 150 ms. After a system boot (power on,
RESTart
, or
RESEt
), the status polling is
ready after the first
cmd:-
prompt.
Construction of the status byte (status-level 1):
Bit 7 6 5 4 3 2 1 0
Meaning 1 MODE D STATUS
Bit 7 always 1 to avoid control codes (XON/XOFF, etc).
Bit 3 (DIRECTION bit) reflects the state of the SEND LED. This bit is 1 when the PTC
is the packet sender.
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