Campbell CR10 PROM, Operator'S Manual

Page: 40 / 253

SECTION 1. FUNCTIONAL MODES
1-2
Subroutines 97 and 98 have the unique
capability of being executed when a port goes
high (ports 7 and 8 respectively). Either
subroutine will interrupt Tables 1 and 2 (Section
1.1.3) when the appropriate port goes high.
Port 7 cannot wake the processor, subroutine
97 will be executed at the next 1/8 second
interval after the port goes high. Port 8 will
wake the processor within a few microseconds.
The port triggers on the rising edge (i.e., when
it goes from low to high). If the port stays high
the subroutine is not called again.
1.1.3 TABLE PRIORITY/INTERRUPTS
Table 1 execution has priority over Table 2. If
Table 2 is being executed when it is time to
execute Table 1, Table 2 will be interrupted.
After Table 1 processing is completed, Table 2
processing resumes at the interruption point. If
the execution interval of Table 2 coincides with
Table 1, Table 1 is executed first, then Table 2.
Interrupts by Table 1 are not allowed in the
middle of an instruction or while output to Final
Storage is in process (flag 0 is set high). The
interrupt occurs as soon as the instruction is
completed or flag 0 is set low.
Special subroutines 97 and 98, initiated by a
port going high (Section 1.1.2), can interrupt
either Table 1 or 2 or can occur when neither is
being executed. These subroutines can
interrupt a table while the Output Flag is set.
When the port activating 97 or 98 goes high
during the execution of a table, the instruction
being executed is completed before the
subroutine is run (i.e., as if the subroutine was
called by the next instruction).
The priority is 98, 97, Table 1, Table 2. If both
97 and 98 are pending (ports go high at the
same time or both go high during the execution
of the same instruction in one of the tables), 98
will be executed first. If 97 or 98 has not
interrupted a table then neither table can
interrupt it. 97 and 98 cannot interrupt each
other. However, when 97 or 98 interrupts a
table, it is as if the subroutine were in the table
(e.g., if 98 interrupts Table 2, either Table 1 or
97 can interrupt it).
While 97 or 98 is being executed as a result of
the respective port going high, that port
interrupt is disabled (i.e., the subroutine must
be completed before the port going high will
have any effect).
1.1.4 COMPILING A PROGRAM
When a program is first entered, or if any
changes are made in the *1, *2, *3, *A, or *C
Modes, the program must be compiled before it
starts running. The compile function checks for
programming errors and optimizes program
information for use during program execution.
If errors are detected, the appropriate error
codes are indicated on the display (Section
8.10). The compile function is executed when
the *0 , *6, or *B Modes are entered and prior to
saving a program listing in the *D Mode. The
compile function is only executed after a
program change has been made and any
subsequent use of any of these modes will
return to the mode without recompiling.
When the *0, *B, or *D Mode is used to
compile, all output ports and flags are set low,
the timer is reset, and data values contained in
Input and Intermediate Storage are reset to
zero.
When the *6 Mode is used to compile data
values contained in Input Storage, the state of
flags, control ports, and the timer (Instruction
26) are unaltered. Compiling always zeros
Intermediate Storage.
1.2 SETTING AND DISPLAYING THE
CLOCK - *5 MODE
The *5 Mode is used to display time or change
the year, day or time. When "*5" is entered, the
time is displayed and updated approximately
once a second or longer depending on the rate
and degree of data collection and processing
taking place. The sequence of time parameters
displayed in the *5 Mode is given in Table 1.2-
1.
To set the year, day or time, enter the *5 Mode
and advance to display the appropriate value.
Key in the desired number and enter the value
by keying "A". When a new value for hours and
minutes is entered, the seconds are set to zero
and current time is again displayed. To exit the
*5 Mode, key "*" and the mode you wish to
enter.
When the time is changed, a partial recompile
is done automatically to synchronize the
program with real time.
Changing time will also affect the output and
execution intervals during which time is
changed. Because time can only be set with a
1 second resolution, execution intervals of 1