Manual

6-8 Escape Sequences
ESC.H [(<Block Size or Xoff Threshold>) ; (<Enquiry Character>) ;
(<Acknowledge String or Xon Trigger String>)] :
Set Handshake Mode 1
This command sets the same parameters as the ESC.I command, but enables Handshake
Mode 1. In Handshake Mode 1, certain parameters of the
ESC.M and ESC.N commands
will affect the response to the Enquiry Character or the Xon Trigger String, according to the
Applicable Output Modifiers tables on page 6-10.
ESC.I [(<Block Size or Xoff Threshold>) ; (<Enquiry Character>) ;
(<Acknowledge String or Xon Trigger String>)]:
Set Handshake Mode 2
This command sets the same parameters as the ESC.H command, but enables Handshake
Mode 2. In Handshake Mode 2, the response to the Enquiry Character or the Xon Trigger
String is affected by the Turnaround Delay, but not by the other parameters of the
ESC.M
and
ESC.N commands. See the Applicable Output Modifiers table on page 6-11.
If the second parameter is nonzero, the Enq/Ack handshake is enabled and the parameters
are interpreted as follows: the first parameter is <Block Size>, the second is <Enquiry
Character>, and the third is <Acknowledge String>. If the second parameter is zero, the
Enq/Ack handshake is disabled and the parameters are interpreted as follows: the first
parameter is <Xoff Threshold>, the second parameter is zero, and the third parameter is
<Xon Trigger String>.
Enq/Ack Handshake:
The DEC <Block Size> parameter becomes the block size used in Enq/Ack and Hardwired
DTR handshakes. Values greater than 256 are interpreted as 256. Default is 80.
The ASC <Enquiry Character> parameter, if nonzero, enables the Enq/Ack handshake and
specifies the character which will be recognized by the Automove System as the Enquiry
Character. The default is zero. The most common value to use is 5, corresponding to the
ASCII ENQ character.
The STR <Acknowledge String> parameter becomes the Acknowledge String which is
transmitted after the <Enquiry Character> is received, when the buffer has room for a
block of characters. The default is the null string. If <Acknowledge String> is null, no
characters will be transmitted when the buffer has room. The most common value to use is a
6, which establishes the ASCII ACK character as the Acknowledge String.
Example: the sequence
ESC.I;5;6:ESC.M10: sets up a "normal" ENQ/ACK handshake
using the ASCII characters ENQ and ACK, with a 10 millisecond turnaround delay.