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SUMMARY
PLC RESOURCES:
INPUTS(I) These are elements used to collect and adapt the signal received
from the outside
OUTPUTS(O) These are elements used to send outside signals with which the
plc operates in its environment
MARKS(M) These are elements capable of memorizing information regarding the
internal status of the plc, acting like an internal relay
REGISTERS(R) These are elements which allow a numerical variable or discrete
variable status to be memorized
TIMERS(T) These are elements which alter their output for a specific time
(Time constant)
COUNTERS(C) These are elements capable of counting up or down a specific
number of events
INPUTS
They supply information to the PLC from signals received from the outside
world. The inputs are referenced by indicating the letter I and its number,
ex I01. The maximum inputs that the CNC can have is 256 inputs, depending
on the configuration.
OUTPUTS
PLC sends information outside through its outputs. They allow the PLC
to turn on/off different devices. The maximum outputs that the CNC can
have is 256 outputs depending on the configuration. With the Axes module
only, there are 24 outputs. The outputs are referenced by indicating the
letter O and its number, ex O16
MARKS
A mark, or internal relay, is a memory in which the information defined
by the user is retained. Each mark stores a bit or logic state
Marks are referenced by indicating letter M and its number
MEANING
------------------------------------------------------------------------------------------------------------------------ User marks M1 - M2000
Arithmetic flag marks M2001 - M2008
Clock marks M2009 - M2024
Fixed status marks M2046 & M2047
Marks associated with messages M4000 - M4127
Marks associated with errors M4500 - M4563
Screen marks M4700 - M4955
CNC communication marks M5000 - M5957
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REGISTERS
They allow a numerical value to stored in 32 bits or aid in CNC-PLC
communications with logic CNC inputs - outputs Their value will be
stored in memory even when the system is turned off unless erased in
the initial cycle. This is encouraged unless there is a specific register
value you want to remember. They are represented by the letter R and
there are 256 user registers and other special registers. It is also possible
to reference a bit of a register. eg. B3 R200 (bit 3 of register 200)
MEANING
------------------------------------------------------------------------------------------------------------------------- User registers R1 - R256
Special registers R500 - R559
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TIMERS
A Timer is resource capable of maintaining its output at a specific logic
level during a pre-selected time, after which the output changes its status
TEN:ENABLE INPUT In order for the timer to count time, the TEN INPUT must be at a logic level
of “1”.
TRS:RESET INPUT When there is a transition from logic level “0” to “1”, the T status sets to
“0” as well as th elapsed time t an the timing stops, if it was running.
TG1/4:TRIGGER INPUTS
The triggering is originated by a change of the logic state of any of these
inputs from “0” to “1” depending on the selected input
ex. TG1 20 100 Indicates the trigger input1 of timer 20 with a time constant of 1 second
TG4 32 R40 Indicates the trigger input4 of the timer 32 with a time constant equal to
the value stored in register 40, in hundredths of a second.
*T:STATUS
This OUTPUT indicates the logic state of the timer.
*t:ELAPSED TIME
16 bit binary output indicates the elapsed time within the timer.
can only be used in arithmetic and comparison operations
ex. CPU T1 GT 1000 This expression will check(cpu) whether the time elapsed in t1 is greater
(GT) 1000 hundredths of a second (10 seconds)
OPERATING MODES OF A TIMER
MONOSTABLE The timer generates a pulse whose width is determined by the time constant
ACTIVATION DELAY This mode allows the creation of a delay from the time the trigger input TG2
is activated to the time the output T of the timer is activated.
eg. I2 = TG1 T1 5000
T1 = O2
when input 2 is turned on, O2 will be on for 5 seconds.
DEACTIVAT. DELAY This mode allows to create a delay from th time TG3 is deactivated to the time
output T of the timer is deactivated.
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eg. I3 = TG2 T1 5000
T1 = O2
when input 2 is turned on, O2 will wait 5 seconds then turn on.
SIGNAL LIMITER This mode allows to limit the duration of the signal at input TG4
COUNTERS
The counter is an element capable of counting up or down
*CEN:ENABLE INPUT *CEN must be”1” in order to count.
*CUP:UP-COUNT INPUT Each leading edge at this input increments the count by one
*CDW:DOWN-COUNT I/P Each leading edge at this input decrements the count by one
*CPR:PRESET INPUT A leading edge at this input will preset the counter with the specified
count
ex. CPR 12 -10 indicates the preset input of counter 12 with an initial count of -10
*C:STATUS This output indicates, with a logic level, the status of the counter
*c:COUNT VALUE This 16 bit output indicates the count value; can only be used for
arithmetic and comparison operations.
eg. DFU I5 = M1
M1 AND M2018 = CUP3
CPS C3 GE 300 =O20
When I5 is high, M1 and M2018 (4second pulse) is also high, it will activate
Counter 3. When the count is at 300 (300 seconds, 5 min), o20 will turn on.
PROGRAMMING:
The PLC program is structured by modules and it could cocnsist of:
First Cycle module(CY1)
Main module(PRG)
Periodic Execution module(PE)
Programming with real values allows optimum execution speed of the plc
DIRECTING INSTRUCTIONS:
END: Indicates the end of any module
REA: Indicates that from that point on real values must be used
IMA: Indicates that from that point on image values must be used
PRG.PE1,CY1 Indicates the beginning of the modules that can be defined in plci user prog.
END End of the module
L Label. used to identify a program line
DEF Definition of symbol. Allows a symbol to be associated with any plc variable
FLANK DETECTION
DFU: Returns a “1” when a leading edge(up flank) has occurred during the
running cycle at the input, output, or mark specified
DFD: Returns a “1” when a trailing edge(down flank) has occurred during the
running cycle at the input, output or mark specified
COMPARISON OPERATORS
CPU: Unsigned NOT
CPS: Signed Comparison AND
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GT: Greater than OR
GE: Greater or equal XOR
EQ: Equal ( )
NE: Not equal
LE: Less or equal
LT: Less than
ACTION INSTRUCTIONS
BINARY
assignment: The value(0/1) of the logic expression can be assigned to specified variable
conditional: SET The result of a logic action is 1, this action assigns a 1 to the I,O,M,R
RES The result of a logic action is 1, this action assigns a 0 to the I,O,M,R
CPL The logic expression is a 1, this action complements the status of I,O,M,R
The logic expression is a 0, this action will not modify the status
SEQUENTIAL Allows the program sequence to be interrupted and continue on another line
jump (JMP) The expression is 1, the program jumps to the line and continues the program
calling a subroutine
(CAL) The expression is 1, the program jumps to the line and continue the program
return (RET) The expression is 1, this action indicates the end of subroutine & returns
ARITHMETIC ACTION
MOV Transfers the logic status of the origin indicated to specified destination
Source Destination Source Code Dest. Code #bits to transmit
----------------------------------------------------------------------------------------------------------------------------MOV I1/256 I1/256 0 (Bin) 0 (Bin) 32
O1/256 O1/256 1 (BCD) 1 (BCD) 28
M1/5957 M1/5957 24
T1/256 R1/559 20
C1/256 16
R1/559 12
# 8, 4
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ADS,SBS,MLS,DVS,MDS
If the logic expression result is 1, this will allow addition, subtraction,
multiplication, division, and module or remainder of division
LOGIC ACTION
AND, OR, XOR The logic expression result is 1, these actions allow the logic operations
SPECIFIC ACTION
ERA Allows inputs, outputs, marks, or registers to be erased
CNCRD Allows reading of inernal variables
CNCWR Allows writing of internal variables
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