Siemens SIMATIC S7 System Manual page 341

S
A signal board (SB) expands the onboard I/O to include a few additional I/O points. An SB
with 2 digital outputs can be used as pulse and direction outputs to control one motor. An SB
with 4 digital outputs can be used as pulse and direction outputs to control two motors. Built-
in relay outputs cannot be used as pulse outputs to control motors.
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 basic motion control instructions), the corresponding output addresses (Q0.0 to
Q0.3, Q4.0 to Q4.3) 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 does not write that value to the physical output.
Table 9- 21 Maximum number of controllable drives
Type of CPU
CPU 1211C DC/DC/DC
AC/DC/RLY
DC/DC/RLY
CPU 1212C DC/DC/DC
AC/DC/RLY
DC/DC/RLY
CPU 1214C DC/DC/DC
AC/DC/RLY
DC/DC/RLY
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
① PROFINET
② Pulse and direction outputs
③ Power section for stepper motor
④ Power section for servo motor
The DC/DC/DC variants of the CPU S7-1200 have onboard
outputs for direct control of drives. The relay variants of the
CPU require the signal board with DC outputs for drive
control.
No SB installed
2
0
0
2
0
0
2
0
0
102BTechnology instructions
9.3 Basic motion control
With an SB
(2 x DC outputs)
2
1
1
2
1
1
2
1
1
With an SB
(4 x DC outputs)
2
2
2
2
2
2
2
2
2
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