Table of Contents
Advertisement
mined in one operation by comparing a seven with the
data in the assigned core storage position.
After the first 20 terminal point contacts have been
scanned and entered in core storage, the terminal ad-
dress in
TAS
is advanced by one and the next 20 terminal
point contacts are scanned and entered into succeed-
ingly higher-numbered core storage positions. This
operation is continued until all addresses on one "half"
of the terminal block have been addressed, and the
status of their terminal points read into core storage.
The entire operation is performed by only one instruc-
tion. The second group begins with the P address
+
7,
and so on. The highest-numbered core storage position
required for an instruction that scans the maximum
of 200 contacts is P
+
69 (70 positions). The exact
range of addresses in core storage for any instruction is
P through P
+
7 (10 - Qll) - 1
where Qll is the digit in that position of the instruction.
PROGRAM INSTRUCTION TIME
The elapsed time required for this instruction varies
according to the number of 20-point groups scanned.
It should be noted that the scanning time for each
terminal address is the same whether the entire 20
points are connected or not. The formula for comput-
ing the total time, in microseconds, for each program
instruction is as follows:
T
=
160
+
175 (10 - Qll)
Qll
=
digit in that position of instruction
A group of points must not be addressed more often
than once every 1.5 milliseconds.
Select Manual Entry Switches
SLME 86 or
Q7
of 8
Description. This instruction is used to program the
Manual Entry special feature. The seven digits in the
1711 Manual Entry switches are read into the P address
and into successively higher-numbered core storage lo-
cations. The high-order digit is flagged. Core storage
data that is replaced, including flag bits, is lost.
The Select Manual Entry Switches instruction may
be executed while the Multiplexer Busy indicator is on.
The Q8 - Qll digits of the instruction are not used.
Execution Time. T
=
300
Operating Contact Points and
Set-Point Positioners
48
Select Address and Contact Operate
Select Analog Output and Signal
Select Address and Contact Operate
SACO or 84 with
Q7
of 2
Description. This instruction is used to program the
special feature, Contact Operate. The contact in the
1712 whose terminal address is specified by the Qu - Qll
positions of the instruction is closed for 50 ms. The
closed contact completes a circuit to a customer device
(motor, light, alarm, etc.) . The customer supplies the
voltage required to power the circuit.
Execution Time. The computer is released after
160 fLsec. The Multiplexer Busy indicator and the
selected multiplexing relay are activated for 50 ms.
Select Analog Output and Signal
SAOS or 84 with
Q7
of 3
Description. This instruction is used to program the
special feature, Analog Output, as follows:
I. A Select Analog Output and Signal instruction
that specifies the up or down address of each spp
(set-point positioner) to be adjusted is executed.
2. After selection of spp addresses, another Select
Analog Output and Signal instruction specifying
the slew or trim address is executed.
All Select Analog Output and Signal instructions,
including those for spp selection and slew or trim selec-
tion, must be executed while the Analog Output Setup
indicator (28) is on to ensure complete slew or trim
adjustments.
Execution Time. 160 fLsec are required to execute
this instruction. The computer is free to execute other
instructions after this time. The Multiplexer Busy in-
dicator is on for 3.75 ms, the time required to pick an
Analog Output latching relay. A complete Analog Out-
put cycle, which includes a selection of channels (.7
second) and slewing (2.5 seconds) or trimming (.5
second) , requires 3.6 seconds. At least two Select Ana-
log Output and Signal instructions are required dur-
ing the. 7 -second setup time - one or more instructions
for Analog Output channel selection and one for slew
or trim selection.
Interrupt Routine Instructions
Mask
Unmask
Branch Out
Branch Out and Load
These four instructions are used to control the com-
puter program when process or internal (1710) inter-
rupts occur. They enable the program to branch to
special routines in order to satisfy the interrupt con-
dition, and then return to the main program.
Advertisement
Table of Contents
