2. Controller Architecture and Program Operation
GEM80-400
Page 2-6
ALSPA GEM80-400 SERIES CONTROLLERS TECHNICAL MANUAL
Issue 3 04/99
Table 2.1 Error Categories.
Category
Definition
Action by Controller
Catastrophic
Error
Controller totally unreliable
(e.g. firmware corrupted).
(a) Watchdog contacts opened.
(b) Controller halted.
(c) No communication to a suitable GEM
80
programming tool (no error message).
Fatal Error
Failure of controller functions
(e.g. Basic I/O failure).
(a) Watchdog contacts opened.
(b) Controller halted.
(c) Controller will communicate with a
suitable GEM
80 programming tool (error
message generated).
Lock Error
Error which can be
recovered by clearing the
program store and reloading
the program (e.g. program
corrupt on power up).
(a) Watchdog contacts open.
(b) Program halted.
(c) Controller will communicate with a
suitable GEM
80 programming tool.
2.3.
System Self-tests
While the GEM
80-400 system is 'powered up' the system undergoes a number of
continuous tests. These are:
(1)
Read/write memory test of all used RAM. This includes system work space,
object
code and data table RAM.
(2)
A 16-bit checksum test of the following data areas: source code, object
code, V-
table, P-table and EPROM.
Note...
(i) CRC of operating system EPROM is checked at system power up.
(ii) Source code only checked before any compilation takes place.
(3)
The power supply to the processor module.
(4)
The battery power supply
(5)
The system watchdogs.
(6)
The bit unpacking logic.
The above tests, in their entirety, are performed on power up before the system is
allowed to 'run'. If tests (1), (2), (3), (5) or (6) fail it is deemed a fatal error; the
system is 'halted' (if not already), 'locked' and an error message issued to a
suitable GEM
80 programming tool, if connected. Information on the self-test
system is detailed in Chapter 9 of this manual.
Note...
Some errors, notably error number #710 'Battery Failure' do not generate
any of the above error status flags, in this case the error message is sent to the
Printer/Programming port and a fault bit is set in F2.4 but the Watchdog contacts
are not opened and the system is not halted.
2.4.
States of the GEM 80-400 Controller
The current 'state' of the controller is displayed on the processor front panel
display via simple mnemonics, and on the display of a suitable GEM
80