HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

666 AppendixL
A Programmer’s Guide to VPLUS
VPLUS & Multiplexers
2. When you want to connect the terminal to an HP 2334A CLUSTER (PAD) you must
change the following specifications:
DATACOMM:
RecvPace : Xon/Xoff use XON/XOFF handshake
XmitPace : Xon/Xoff on send and receive transmission.
TERMINAL :
InhHndShk : YES disables the use of DC1-
Inh DC2 : YES and of DC1/DC2/DC1-
handshake on blockmode.
With the reconfiguration of the terminal you switch off the handshake normally used. For
example: you do not use an XON and XOFF protocol between the computer and the terminal
to control the dataflow on a direct line. The terminal does not transmit XON or XOFF (DC1
and DC3) automatically, this only can be sent by pressing the ‘
CTRL Q’ or ‘CTRL S’ key
combination.
The CLUSTER must be configured to use the PROFILE 1 to work properly.
The HP 3000 must have a PAD-terminal configured in the system like this:
DRT# = ldev of inp UNIT = 0 CHANNEL = 0
TYPE = 16 SUBTYPE = 0 REC.WTH = 40
DRIVER NAME = IOPAD0 DEV.CLASS = PADTERM
If you want to use VPLUS on the terminal connected to an HP 3000 via a port on a PAD
(HP 2334A), you need a terminal supporting blockmode. For example:
HP 2382A, HP 2392A-2394A, HP 700/92-700/94 or similar.
One of the problems will be the transmission of a block after pressing the ENTER key.
Normally the HP 3000 will control the dataflow with the normal DC1 and DC3 handshake
(XON / XOFF). When starting VPLUS, the Application reconfigures the terminal, so it will
use a handshake named DC1/DC2/DC1. By using this protocol, the computerside tells the
terminal, that the FORM is transmitted completely and that the user may start entering
data to the FORM. This is initiated with the signal DC1.
When the input is terminated either with an
ENTER, a SELECT or a function-key, the
terminal tells the ready-state of the data to the computer with the DC2-signal. The
computer now will initiate the transmission with the signal DC1.