Commissioning
6-6 AutomationSystem S7-400 Hardwareand Installation
A5E00850741-01

Communication between Programming Device and CPU

The following conditions apply when communicating between a programming
device and a CPU:
•Youneed a programming device with STEP 7.
•The CPU can communicate with the programming device in the following
modes: RUN, STOP,STARTUP,and HOLD.

Operator Control

A description of operator control of communication between CPUs and
programming devices can be found in the STEP 7 manuals.
6.4 Switching On an S7-400 for the First Time

Switching On an S7-400 for the First Time

First switch on the power cutout.
Then set the standby switch of the power supply module from the standby setting
to the Isetting(output voltages at rated value).
Result:
•On the power supply module, the green 5 VDC and 24 VDC LEDs light up.
•On the CPU
-- The yellow CRST LED lights up;
-- The yellow STOP LED flashes for three seconds at 2 Hz. During this time the
CPU automatically executes a reset.
-- The yellow STOP LED lights up after the automatic reset.
If the red BAF LED and one of the yellow LEDs (BATTFor BATT1F or BATT2F)
light up on the power supply module, check the backup battery/batteries, the
setting of the BATTINDIC switch, or read the section on controls and indicators of
the power supply modules in Chapter 3 of the Reference Manual, Module
Specifications.

Switching On an H System for the First Time

First switch on the master device and then the standby device. In each case,
proceed as described above.