Parker Hannifin S.p.A. - Divisione S.B.C. LVD User’s Manual
65
Note that parameters Pr23, Pr24, Pr25, Pr26, Pr27, Pr29, Pr31 and Pr34 are bytes like Pb42 and
Pb94; therefore, mathematical operations cannot be used for these parameters and logical operations
must be used to alter their values.
FIN instruction. Three instructions are provided for high speed input acquisition: in this case the
scan is executed at 512ms (normal scanning is 6.144mS). If used, FIN instructions must be the first
PLC instructions. The first FIN instruction copies digital input 1 into bit y of parameter Pb40
(second operand=0) or Pb70 (second operand =1). The second FIN instruction copies digital input 2
into bit y of parameter Pb40 (second operand=0) or Pb70 (second operand=1). The third FIN
instruction copies digital input 3 into bit y of parameter Pb40 (second operand=0) or Pb70 (second
operand=1). If the second operand is added to value 2, before the input is copied it will be inverted.
If a FIN instruction is included at any other position in the program it will have no effect. FIN
instructions can be enabled/disabled by means of a bit parameter for each FIN: 1st FIN enabled if
b94.5=0; 2nd FIN enabled if b94.6=0; 3rd FIN enabled if b94.7=0. A FIN instruction in the PLC
program after the first three instructions or after any other type of instruction will be disregarded.
There are two timers Pr92 and Pr93 at the disposal of the user. To use the first timer simply load
the time in terms of number of samplings (6.144 mS) in parameter Pr92: for example Pr92=100 is
equivalent to 614 milliseconds. Pr92 automatically decreases through time, bit b99.0 remains on
zero until the timer interval has elapsed; when Pr92=0 then b99.0=1. The same functionality applies
to the second timer regarding parameter Pr93 and bit b99.1. Attention: note that Pr92 Pr93 b99.0
and b99.1 are refreshed only before the pico-PLC program scan.
The maximum number of instructions is 128. Note that mathematical operations occupy the
space of two logical operations so when they are used the maximum number of instructions
available is decreased accordingly.
The PLC program must always be terminated with an END instruction.
The pico-PLC program can be edited on a PC (see Programming with PC2LVD) or directly from
the keypad. In this latter case, to facilitate procedures, when you need to delete an instruction, select
it and then press [M] to display the type of instruction; now keep [M] pressed and simultaneously
press [-]; when both keys are released the instruction will be deleted. On the contrary, in order to
add an instruction after In06 for example, select the next instruction In07, press [M] to display the
type of instruction; now keep [M] pressed and press [+] simultaneously; when both keys are
released an FIN instruction will be inserted. When inserting instructions make sure that the
instructions in the program are no more than the maximum number or you will lose the last one(s).
The pico-PLC program can be edited or altered only when the PLC is in stop status (b99.13=0).
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