FM 456-2 Functions and Technical Data
4-7
FM 456-2 Application Function Module Installation, Hardware, and Startup
C79000-G7076-C458-01
Table 4-4
Meaning of the Status and Fault Indicators on the FM 456-2
Indicator
Description
Meaning
SD(green)
Access to memory card
Lights when read or write access to
the memory card occurs.
HD
(green)
Access to hard disk
Lights when read or write access to
the hard disk on the mass storage
module occurs.
USR1
(yellow)
Special indicator for the user pro-
gram (user)
Can be allocated by the user (see
programming manual).
USR2
(yellow)
Special indicator for the user pro-
gram (user)
RUN
(green)
“RUN” status indicator
Lights if the system software is
loaded and user programs are run-
ning
(write accesses to the I/O are en-
abled)
STOP
(yellow)
“STOP” status indicator
Lights when the user program of
the programmable module is not
controlling the process (write
accesses to the I/O are not
enabled)
Flashes when a memory reset is
requested or is being performed.
All indicators light briefly as a self-test following an MRES (see Page 4-5) or switching on
of the power supply.
4.5
Memory Card
The FM 456-2 application function module provides a facility to use memory cards
as data medium or mass storage. This section provides you with information on
how to use this facility.
Note
If a power failure occurs during write access to the memory card, the entire
content of the memory card may be corrupted under worst case conditions.
Please note that, unlike a diskette, the memory card with flash EPROM is only
suitable for a limited number of write operations.
A memory card simulates a diskette drive from which the operating system can be
booted. It can also be used for changing user software and data.
For the FM 456-2, memory cards with flash EPROM are available (see Section 5,
“Ordering Information”).