Siemens SIMATIC S7 System Manual page 438

Communication
8.5 PROFIBUS
The following table summarizes the status indications signified by the EM DP01 status LEDs:
Table 8- 5
Description
24 V DC user power good
No 24 V DC user power
Internal module failure
Upon startup, until the
EM DP01 is logged in by
the CPU, or if there is a
fault in the EM DP01
While the EM DP01 is
waiting on configuration
and parameterization from
the S7-200 SMART CPU,
or during a firmware up-
date
No fault is present;
EM DP01 is configured
No DP error
DP communications inter-
rupted; Data Exchange
Mode stopped
Parameterization / configu-
ration error (from the
DP Master)
Data Exchange Mode
inactive, or DP communi-
cations interrupted
Data Exchange Mode
active
438
EM DP01 PROFIBUS DP module status LEDs
POWER LED
(Green)
Green
Off
DIAG LED DP ERROR
(Dual Red / LED
Green) (Red)
Red
Flashing red
Flashing green
Green
Off
Red
Flashing red
System Manual, V2.3, 07/2017, A5E03822230-AF
DX MODE LED
(Green)
Off
Green
S7-200 SMART