Extended instructions
8.6 Pulse
S7-1200 Programmable controller
368 System Manual, 03/2014, A5E02486680-AG
Table 8- 151 SB signal board output: maximum frequency (optional board)
Pulse and direction
output
A/B, quadrature, up/down,
and pulse/direction
Note
The maximum pulse frequency of the pulse output generators is 1 MHz for the CPU 1217C
and 100
KHz for CPUs 1211C, 1212C, 1214C, and 1215C; 20 KHz (for a standard SB); or
KHz (for a high-speed SB). However, STEP 7 does not alert you when you configure an
axis with a maximum speed or frequency that exceeds this hardware limitation. Proble
ms
can result with your application, so always ensure that you do not exceed the maximum
pulse frequency of the hardware.
You have the option to rename the pulse generator, add a comment, and assign parameters
as follows:
● Pulse generator used as follows: PWM or PTO (choose PWM)
● Output source: onboard CPU or SB
● Time base: milliseconds or microseconds
● Pulse width format:
– Hundredths (0 to 100)
– Thousandths (0 to 1000)
– Ten-thousandths (0 to 10000)
– S7 analog format (0 to 27648)
● Cycle time (range is 0 to 16,777,215): Enter your cycle time value. This value can only be
changed in Device configuration.
● Initial pulse width: Enter your initial pulse width value. The pulse width value can be
changed during runtime.
Enter the start address to configure the output addresses. Enter the Q word address where
you want to locate the pulse width value.
Note
Pulse-train outputs cannot be used by other instructions in the user program
When you configure the outputs of the CPU or signal board as pulse generators (for use with
the PWM or motion control instructions), the corresponding outputs addresses are removed
from the Q memory and cannot be used for other purposes in your user program. If your
user program writes a value to an output used as a pulse generator, the CPU doe
s not write
that value to the physical output.
To Next Page
Loading...
