Hitachi NT2021XA, Instruction Manual

Page: 56 / 84

Chapter 2 Syntax
2-40
TC (0) to
TC (7)
Variable name Range of values Default Unit Data size Attribute
Timer counters 0 to 2
31
-1 0 10 ms
Unsigned
2-word data
Readable
and writable
- Explanation
These variables can be used to monitor the counts of the timer counters. The timer counters “TC (0)” to “TC (7)” usually
operate as 31-bit free-running timer counters that start simultaneously with user program startup and are incremented in a
10-ms cycle.
When a timer-start instruction (timer set) or delay operation instruction (delay on or delay off) is executed, the timer counter
corresponding to the instruction operates as the counter for output to a specified timer contact. In this case, the counter is
cleared to zero when the instruction is executed, starts counting, and then stops counting upon reaching the specified count.
When a timer-stop instruction (timer off) is executed, the timer counter corresponding to the instruction is cleared to zero and
operates as a 31-bit free-running timer counter that is incremented in a 10-ms cycle.
- Sample program : Program to accelerate the motor step-by-step by using a free-running timer
(Code area [Code Window])
Label Mnemonic parameter1 parameter2 parameter3 parameter4 parameter5
㩷
㩷 㩷 䋺 㩷 㩷 㩷 㩷 㩷 㩷
㩷
ACCEL=
㩷 㩷
1000
㩷 㩷
: Set the acceleration time to 10 seconds.
㩷
DECEL=
㩷 㩷
1000
㩷 㩷
: Set the deceleration time to 10 seconds.
㩷
SET-Freq=
㩷 㩷
0
㩷 㩷
: Set the output frequency to 0 Hz.
LOOP FW= 1
㩷 㩷 㩷
: Start forward rotation of the motor.
㩷
if TC(5) < U(00) then LBL1 : When TC (5) indicates less than 10 seconds
㩷
if TC(5) < U(01) then LBL2 : When TC (5) indicates less than 20 seconds
㩷
if TC(5) < U(02) then LBL3 : When TC (5) indicates less than 30 seconds
㩷
if TC(5) >= U(03) then LBL4 : When TC (5) indicates 40 seconds or more
LBL1 SET-Freq=
㩷 㩷
1000
㩷 㩷
: When TC (5) is less than 10 seconds,
increase the output frequency to 10 Hz.
㩷
goto LBL5
㩷 㩷 㩷 㩷
LBL2 SET-Freq=
㩷 㩷
3000
㩷 㩷
: When TC (5) is less than 20 seconds,
increase the output frequency to 30 Hz.
㩷
goto LBL5
㩷 㩷 㩷 㩷
LBL3 SET-Freq=
㩷 㩷
6000
㩷 㩷
: When TC (5) is less than 30 seconds,
increase the output frequency to 60 Hz.
㩷
goto LBL5
㩷 㩷 㩷 㩷
LBL4 FW= 0
㩷 㩷 㩷 㩷
: When TC (5) is 40 seconds or more,
decelerate and stop the motor.
㩷
wait RUN = 0
㩷 㩷
: Wait until the motor stops.
㩷
SET-Freq=
㩷 㩷
0
㩷 㩷
: Set the output frequency to 0 Hz.
㩷
TC(5)=
㩷 㩷
0
㩷 㩷
: Clear TC (5) to zero.
LBL5 goto LOOP
㩷 㩷 㩷 㩷 㩷
㩷
㩷 䋺
㩷 㩷 㩷 㩷 㩷 㩷
(Data area [Data Window])
U (00) = 1000 : Set 10 seconds in variable “U (00)”.
U (01) = 2000 : Set 20 seconds in variable “U (01)”.
U (02) = 3000 : Set 30 seconds in variable “U (02)”.
U (03) = 4000 : Set 40 seconds in variable “U (03)”.