Brief Description Of The Moby File Handler - Siemens MOBY I ASM 421 Technical Description

6GT2 097-3AH00-0DA2
1

Brief description of the MOBY file handler

The ASM 421 is a serial interface module for the MOBY I identification system. It can be driven from any
computer, PC or PLC using the 3964R procedure. The MOBY I file handler is implemented on the
ASM 421.
What is the file handler?
The file handler is a data management system for the MOBY I identification system. It consists of a pro-
gram that runs on the interface module. The MDS (mobile data carrier) and SLG (read-write unit) compo-
nents of MOBY I are identical with and without file handler.
For better understanding of the MOBY file handler, it works in much the same way as a floppy disk system.
MOBY I File Handler
MDS:
Data is stored electronically in
the MDS on a memory chip
(RAM or EEPROM).
SLG:
The SLG modulates the data
stream arriving from the ASM
and demodulates the data
stream arriving from the MDS.
The positioning of the MDS
must lie within the transmis-
sion window of the SLG. This
amounts to several centime-
ters.
The MOBY I interface module
(ASM 421) provides the user
interface. A USART module on
the ASM produces the serial
data stream for the SLG.
Subject to change without notice!
RD: 03/02
J31069-D0142-U001-A0-7618
ASM 421 Technical Description
Floppy Disk System
Floppy Disk:
Data is written magnetically on
a floppy disk.
Floppy Drive:
The floppy drive converts the
data impulses arriving from the
PC into a write string for the
read/write head (or vice versa)
The floppy disk must be posi-
tioned very exactly over the
read/write head as this gener-
ates only very small magnetic
fields.
A PC controls the floppy drive
and exchanges data with it via
a parallel interface. The coding
and decoding of the data takes
place in a floppy controller in
the PC.
6GT2 002-0DA00
– 2 –
6GT2 002-0DB00
6GT2 002-0DC00
ASM 421 / V.24
ASM 421 / RS422
ASM 421 / TTY