Burster 9180, Manual

Page: 90 / 109

Model 9180
burster
Digital Panelmeter
Page 4-46
4.5 BCD output option
4.5.1 Introduction
The BCD output option supplies 5 1/2 digits in BCD code.
Using the
TRISTATE
, the output remains highly resistive so that various display instruments can
use the same communications bus.
All of the outputs are compatible with
TTL
or 24 V logic and are optically isolated with respect to
the input signal to the extent that the card is supplied to an external voltage between 5 V and
24 V.
As long as the
TRISTATE
input is set to "
low
", the data output is updated in the same cycle as
the data appears in the display. If the
TRISTATE
input is set to "
high
", the impedance of all the
outputs including DATA VALID is increased so that the same bus can also be used for other
applications.
The
DATA VALID
signal is updated when the data are available in the communication bus.
When the display is on
HOLD
the data output is also stopped.
The output signals can operate with positive or negative logic. The selection of the logic type is
performed by interchanging the ICs of the option card as well as resetting two connectable
jumpers. Programming using the keyboard is not necessary.