User Manual

PLC concepts made easy
4.5 Pulse outputs
Easy Book
68 Manual, 03/2014, A5E02486774-AF
Note
Do not exceed the maximum pulse frequency.
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
200 KHz (for a high
-speed SB).
The four pulse generators have default I/O assignments; however, they can be configured to
any digital output on the CPU or SB. Pulse generators on the CPU cannot be assigned
to
distributed I/O.
When configuring the basic motion instructions, be aware that STEP
7 does
not
alert you if
you configure an axis with a maximum speed or frequency that exceeds this hardware
limitation. This could cause problems with your application, so always ensure that you do not
exceed the maximum pulse frequency of the hardware.
You can use onboard CPU outputs, or you can use the optional signal board outputs. The
output point numbers are shown in the following table (assuming the default output
configuration). If you have changed the output point numbering, then the output point
numbers will be those you assigned. Note that PWM requires only one output, while PTO
can optionally use two outputs per channel. If an output is not required for a pulse function, it
is available for other uses.
The four pulse generators have default I/O assignments; however, they can be configured to
any digital output on the CPU or SB. Pulse generators on the CPU cannot be assigned to
SMs or to distributed I/O.
Table 4- 6 Default output assignments for the pulse generators
Description
Pulse
Direction
PTO1
Built-in I/O
Q0.0
Q0.1
SB I/O
Q4.0
Q4.1
PWM1
Built-in outputs
Q0.0
-
SB outputs
Q4.0
-
PTO2
Built-in I/O
Q0.2
Q0.3
SB I/O
Q4.2
Q4.3
PWM2
Built-in outputs
Q0.2
-
SB outputs Q4.2 -
PTO3
Built-in I/O
Q0.4
1
Q0.5
1
SB I/O
Q4.0
Q4.1
PWM3
Built-in outputs
Q0.4
1
-
SB outputs
Q4.1
-