8. Commissioning
GEM80-400
Page 8-12
ALSPA GEM
80-400 SERIES CONTROLLERS TECHNICAL MANUAL
Issue 3 04/99
Note...
The Tx LEDs on the processor module, when it is configured as a Control
Port, light when it attempts to transmit, even if no serial link connections are
made.
There are several types of serial link. To keep this chapter reasonably brief, we
cannot tell you in detail how to commission every individual type. Chapter 4 of
this manual tells you what data to preset in the P-table for the various types of
link, which are listed below:
(1)
Printers or programming tools. Where you simply connect a printer,
programming
tool or VDU to your GEM
80-400 Controller. Printer ports can
be set to either
direct or terminal mode.
(2)
Second, there are ports talking to other GEM
80 controllers and
programming
tools. These can be set to either free-running or
user-controlled mode, with either
standard or flexible table allocation.
Further information and examples of the P-table preset data for the various serial
port configurations are given in the 'Serial Communications Manual', Publication
No.T457.
8.16.1. Printer
Ports
For outputting data to a printer or VDU, include the PRITEXT GEM
80 Special
Function in the program. The Printer port must be preset with the following data
for the printer in use:
-
the baud rate (bit/s),
-
the character format (quantity of bits/character, odd/even/no parity), and
-
any null characters required at the end of a print line (not normally needed
on
printers that have input buffer memory).
If these are correct, you should be able to output data messages from your
program to the printer or VDU. The printer or VDU must, of course, be suitable for
the signal level to which it is connected. The Tx LEDs will light when the GEM
80
Special Function PRINT is set.
8.16.2. Processor Serial Links Connecting Controllers
Where serial links are used to provide communications between different GEM
80
controllers, all the controllers must be commissioned before the serial links can
be commissioned.
The simplest form of serial link is free-running with standard table allocation. For
this type of link, write data into the K-table locations at the controller providing
the control port, and check that it appears in the appropriate J-table locations
of the tributary.
Similarly, if you have placed data into the K-table locations at one of the
tributaries, the tributary should reply and the data should appear in the
appropriate J-table locations at the control port.