Burster 9180, Manual

Page: 66 / 109

Model 9180
burster
Digital Panelmeter
Page 4-22
4.3 RS232 (RS2) option
4.3.1 Introduction
The output option RS232C consists of an additional card (reference
RS2
), which is installed in
the M1 plug-in slot.
The card has a 4-way telephone connection (Western socket).
The RS232 output can be used to establish a communications line with which a master can
request from one or more display instruments data, for example, display value, switching point,
maximum and minimum values, tare values (or offset in the case of a thermometer). Furthermore,
various functions can be performed like tare, deletion of the memory for maximum, minimum and
tare values and changes to the switching points.
Furthermore the instrument is provided with a command with which all the equipment settings can
be copied into a different device of the same type.
The transmission speed can amount to 1200, 2400, 4800 or 9600 baud. The device adressing
is programmable between 00 and 99.
Using the RS232C option you can connect the device to a master unit using the RS232C
interface.
The operating mode is semi-duplex. The series channel is only active, if the device, which is
normally in receiving mode until the message arrives, is in operating mode.
If the device receives a valid message, an action can immediately be performed (tare in display,
deletion of the maximum/minimum value or tare memory, change of switching points) or a
response of the polled device can be transmitted (display value, value of a switching point or the
maximum/minimum value or tare memory). The transmission of the display value can be
requested using an external switch(see page 4-28).
4.3.2 Protocol and commands
Two communication types are provided for: the
DITEL
mode operates with a simple protocol.
Using the
ISO
mode corresponding to the ISO 1745 standard, communication can be performed
more effectively in an environment prone to distortion, as here the validity of a message is tested
during transmission as well as reception.
As the depicted in the function table on page 4-24, the
DITEL Protocol
works with 1 or 2 bytes
depending on the type of command, while the ISO 1745 protocol always requires two bytes per
command.
A example in BASIC in SOURCE CODE you can find
at the end of this manual.