Parker SPD 2 - Page 74

Parker Hannifin S.p.A. - Divisione S.B.C. “SPD” User’s Manual
73
These settings remain active until the next arithmetic operation is executed (the operation is
executed only if the stack bit is equal to 1). A mathematical operation can be executed by
placing the result in one of the constant parameters (Pr71...Pr79) in order to set bit b99.2 and
b 99.3.
If the DIV operation is executed on a double word, the most significant part of the result
contains the remainder of the division, that is, if b94.0=1 and the operation [DIV 79 77 80] is
executed, the result will be Pr80=4 and Pr81=96.
The FIN instruction. Two instructions are available for the fast acquisition of inputs: in this
case the scanning occurs at the rate of 512µs (normal scanning is at the rate of 6.144ms). If
this is used, they must be the first instructions of the PLC. The first instruction FIN copies
digital input 0 to the y bit of the Pb40 parameter (the second operand =0) or Pb150 (the
second operand=1). The second FIN copies digital input 1 to the y bit of the pPb40 parameter
(second operand=0) or Pb150 (second operand=1). If the value 2 is added to the second
operand, the input must be negated before being copied. If an FIN instruction is inserted in a
different position, it will not have any effect. The FIN instructions can be enabled/disabled
using a bit for each FIN: 1° FIN abilitato se Pb94.5=0;2 FIN abilitato se Pb94.6=0. The FIN
instruction inserted in the PLC program after the first two instructions and in any case if it
follows any instruction that is not a FIN instruction is ignored.
The user can make use of two timers, Pr92 and Pr93. To use the first timer load the time as a
number of sampling (6.144 ms) into PR92. For example, Pr92=100 is equal to 614
milliseconds. Pr92 will automatically be decremented as time goes by and the b99.0 bit will
remain set to 0 until the timer has expired. When Pr92=0 then Pb99.0=1. The second timer
works the same way using the PR93 parameter and the b99.1 bit 99.1. Pr92, Pr93, b99.0 and
b99.1 are updated only before the pico-PLC program is scanned.
The maximum number of instructions is 128. The arithmetic operations occupy the space of
two logical operations. If they are used, the maximum number of instructions accepted is
reduced.
The PLC program must always end with the END instruction.
The pico-PLC program can be edited on a PC or directly using the keyboard. In this last case,
in order to facilitate the modification of the program, if you want to delete an instruction, go
to the instruction to be deleted and hit the [M] key. The type of instruction is then displayed.
By holding down the [M] key and pressing the [-] key, the instruction will be deleted when
both keys are released. If you want to add an instruction after the In06, go to the next
instruction In07 and hit the [M] key. The type of instruction is then displayed. By holding
down the [M] key and pressing the [+] key, the FIN instruction will be inserted when both
keys are released. In this last case make sure that the program does not exceed the maximum
limit of the instructions, otherwise the last instructions will be lost. The pico-PLC program
can be edited or modified only when the PLC is in stop (b (99.13=0).