Siemens MOBY I ASM 421 Parts list manual

Table of Contents
Brief description of the
MOBY file handler 1
ASM 421 hardware 2
Programming the
ASM 421 module 3
Cold start and restart 4
Checking entry and exit of MDS
in SLG transmission window 5
System and transmission times 6
Troubleshooting and
error messages 7
Warnings 8
Published in March 2002
6GT2 097-3AH00-0DA2
ASM 421 Interface Module
Technical Description
MOBY I

Safety Guidelines
This manual contains notices which you should observe to ensure your own personal safety, as well to protect the
product and connected equipment. These notices are highlighted in the manual by a warning triangle and are mar-
ked as follows to the level of danger.
!Danger
indicates that death, severe personal injury or substantial property damage will result if proper pre-
cautions are not taken.
!Warning
indicates that death, severe personal injury or substantial property damage can result if proper pre-
cautions are not taken.
!Caution
indicates that minor personal injury or property damage can result if proper precautions are not
taken.
Note
draws your attention to particularly important information on the product, handling the product, or to
a particular part of the documentation.
Qualified Personnel
Only qualified personnel should be allowed to install and work on this equipment. Qualified persons are defined
as persons who are authorized to commission, to ground, and to tag circuits, equipment, and systems in accor-
dance with established safety practices and standards.
Correct Usage
Note the following:
!Warning
This device and its components may only be used for the applications described in the catalog or
technical description, and only in connection with devices or components from other manufactorers
which have been approved or recommended by Siemens.
This product can only function correctly and savely if it is transported, stored, set up, and installed
correctly, and operated and maintained as recommended.
Trademarks
SIMATICand MOBYare registered trademarks of SIEMENS AG.
We have checked the contents of this manual for agreement with the hard-
ware and software described. Since deviations cannot be precluded entirely,
we cannot guarantee full agreement. However, the data in this manual are
reviewed regularly and any necessary corrections included in subsequent
editions. Suggestions for improvement are welcomed.
Disclaimer of Liability
Copyright Siemens AG 1995,2002 All rights reserved
The reproduction, transmission or use of this document or its contents is not
permitted without express written authority. Offenders will be liable for
damages. All rights, including rights created by patent grant or registration of
a utility model or design, are reserved.
Siemens AG
Automation & Drives (A&D)
Systems Engineering (A&D SE)
P.O. Box 23 55, D-90713 Fuerth SiemensAG 2002
Technical data subject to change.
Siemens Aktiengesellschaft Order No. 6GT2 097-3AH00-0DA2

ASM 421 Technical Description 6GT2 097-3AH00-0DA2
– 1 – RD: 03/02
6GT2 002-0DA00 ASM 421 / V.24 Subject to change without notice!
6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY J31069-D0142-U001-A0-7618
Contents
1 Brief description of the MOBY file handler 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 ASM 421 hardware 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 Technical data 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Pin assignments 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2.1 Pin-outs of X1 backplane connector 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2.2 ASM 421 connector system 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Setting the mode of operation 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Hardware planning 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.1 System configuration 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.2 Power supply 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.3 TTY cabling 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.4 RS422 cabling 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.5 V.24 cabling 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.6 STG cabling 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.7 DI/DO cabling 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Programming the ASM 421 module 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 3964R procedure 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Telegram format 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Blocking of long data sequences 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 File handler commands 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.1 FORMAT 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.2 CREATE 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.3 QUEUE-WRITE 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.4 WRITE/UPDATE 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.5 READ 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.6 QUEUE-READ 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.7 DELETE 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.8 COVER 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.9 DIR 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.10 MDS status 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.11 ASM Status 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.12 TRACE 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.13 ATTRIB 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.14 NEXT 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.15 RESET 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4.16 LOAD/MOVE 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 Telegrams from file handler 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.1 Start-up message 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5.2 Change in proximity status 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Cold start and restart 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Checking entry and exit of MDS in SLG transmission window 49. . . . . . . . . . . . . . .
5.1 MDS recognition by field scanning 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Without entry/exit monitoring 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 MDS control using field scanning and 1 DI 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4 MDS control using 2 DIs 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.5 Without entry/exit monitoring 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.6 Special Operating Mode (Test Operation) 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.7 Diagram showing possible MDS states at an SLG 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 System and transmission times 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Troubleshooting and error messages 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 Warnings 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ASM 421 Technical Description6GT2 097-3AH00-0DA2
– 2 –
RD: 03/02 6GT2 002-0DA00 ASM 421 / V.24
Subject to change without notice! 6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY
J31069-D0142-U001-A0-7618
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 Floppy Disk System
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.
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.

ASM 421 Technical Description 6GT2 097-3AH00-0DA2
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6GT2 002-0DA00 ASM 421 / V.24 Subject to change without notice!
6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY J31069-D0142-U001-A0-7618
Similarities between MOBY file handler and a floppy disk
– The user does not access physical memory addresses
– The user addresses the data via logical names, which consist of up to eight letters
– The conversion of the logical names into physical memory addresses is carried out by software
in the interface module:
File handler ↔Disk-Operating-System (DOS)
– Contiguous data blocks are called files
– The management of files of differing lengths is carried out by a software procedure (file handler)
– The memory is divided into 3 areas:
System area
Directory
User data
The system area contains general system data:
– Volume name
– Format and size of memory
– Data coding
All file names and file lengths are stored in the directory. The file handler calculates
the physical addresses of the user data from these entries.
The largest memory area is reserved for user data, which can be stored in any
form(ASCII, binary, hexadecimal, decimal, etc.). The user data is managed by the
filehandler in blocks. On a floppy, these blocks are known as “sectors” or “logical
blocks”.
Advantages of the file handler for the MOBY I user.
– When specifying a system, it is only necessary to define the names (file names) of the individual
data objects that are to be stored on the MDS.
– The project engineer does not need to structure MDS memory at all.
– The list of data objects can be changed or extended as required during detailed planning. The
MDS data structure does not need to be taken into account.
– The lengths of the individual data objects do not need to be known.
– The description of each data object is a name of up to eight letters. The choice of name can be
directly related to the object (e.g., WORKSNO; SERIALNO; QUALITY; ADDRESS; ORDER;
Drillprog; Turnprog; Millprog;...)
– The programmer does not need to work with absolute addresses. Several sources of program-
ming errors are thus excluded (e.g. double addressing, input errors leading to wrong addresses
and file lengths). The file handler converts the file names into physical MDS addresses.
– Details of the files stored on the MDS can be requested by the “directory” command.
– Data objects can be accessed simply and rapidly using the STG 4F service and test unit. This is
of great advantage to commissioning and maintenance personnel.
– The documentation of the MDS memory structure is very simple and easy to understand, con-
sisting only of a list of file names.
– The user can allocate access rights. Unauthorized deletion and overwriting of user data is thus
avoided.

ASM 421 Technical Description6GT2 097-3AH00-0DA2
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Subject to change without notice! 6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY
J31069-D0142-U001-A0-7618
Formats of different MDS memories:
MDS units with various memory sizes are available with MOBY I. Each type of MDS must be formatted
before processing with the file handler. During formatting, the MDS is given a data structure, divided into
system area, directory and user data. The MDS type is passed to the file handler by the FORMAT com-
mand (see section 3.4.1).
The following table shows how the file handler structures the various types of MDS:
05H
85H 8,189 7,154 32 32 7,456 6,464 233 202 32 32
Type
(Hex)
Enter this
parameter
when initi-
alizing
01H
81H
02H
03H
83H
04H
84H
62
MDS capacity
in bytes (gross)
Total MDS
memory size
42 * 1
Max. no. of
files
Max.number of
files that can
1
be stored
User data in
bytes (net)
Max. no. of user
bytes that can be
written to the MDS
Number of
blocks
The product of no. of blocks
Block size
in bytes
and block size gives the user
data length (net) in bytes
62
128
112
2.045
1.778
*
*
*
2
3
3
16
16
45
1.680
1.440
60
12
7
27
5
105
90
6
2
1
1
9
16
16
10
6
7
27
06H
86H 32,765 28,658
*
*
* With ECC operation
64
64 31,488 27,520 246 215 128 128

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2ASM 421 hardware
CPU
EPROM
Backplane connector (X1)
Fuse
(T 315 mA)
Switch bank (S1)
for setting mode of operation
3 LEDs:
red LED: indicates a fault (see table in chap. 7)
yellow LED: indicates that the SLG device is active
green LED: indicates that an MDS is present
9–way subminiature D connector (screw locking)
(X2) for connecting the SLG read/write device
(The SLG can also be connected via the back–
plane connector if required).
Pin Function
1
2
3
4
5
6
7
8
9
reserve
+ transmit
+ receive
reserve
– receive
– transmit
ground () V)
+ 24 V
reserve
housing cable screen
Pin assignments to SLG
MOBY
Error
Active
ANW
housing= connector housing

ASM 421 Technical Description6GT2 097-3AH00-0DA2
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J31069-D0142-U001-A0-7618
2.1 Technical data
Environmental conditions:
– operating temperature: 0 °C to + 55 °C
– storage temperature: – 40 °C to + 70 °C
Degree of protection to IEC 529: IP 00
Serial interface (to computer/PC):
– transmission rate: 2400 to 19200 Baud
– procedure: 3964R; odd/even parity
– cable lengths: TTY 1000 m (shielded)
RS422 1000 m (shielded)
V.24 30 m (shielded)
Serial interface (to SLG):
– transmission rate (gross): 19200 Baud
– procedure: Asynchronous: 8 bit data: even parity
MOBY I: MDS protocol
– cable lengths: SLG dependent; max. 1000 m
(see cable configurations in manual
for configuration, installation and service)
Power supply: 20 to 30 V DC
Current input:
– max. off-load current: 200 mA
(no SLG; DO’s off-load)
Dimensions:
– L x W x H 160 x 100 x 20 (mm)
DI/DO; Select; Request; Error; ANW:
– digital inputs 3
non-floating
logical “0”: 0 V to 8 V
logical “1”: 15 V to 24 V
(Ri = 10 kOhm)
delay: < 10 ms
– digital outputs 5
non-floating
(internal power supply)
short-circuit proof
Imax = 200 mA (per DO; or for 2 DO’s)

ASM 421 Technical Description 6GT2 097-3AH00-0DA2
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6GT2 002-0DA00 ASM 421 / V.24 Subject to change without notice!
6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY J31069-D0142-U001-A0-7618
2.2 Pin assignments
2.2.1 Pin-outs of X1 backplane connector
Z4
Z6
Z8
Z10
Z12
Z14
Z16
Z18
Z20
Z22
Z24
Z26
Z28
Z30
X32
b2
b4
b6
b8
b10
b12
b14
b16
b18
b20
b22
b24
b26
b28
b30
b32
Power supply
Serial interface to user
Optional control and signal line
Optional SLG connection
Protective ground (shield)
Z2
SLG receive +
V.24 RS422 TTY
––
RxD
––
R+
D+
D–
+EM
+SE
––*
V.24 RS422 TTY
TxD
–
GND
E+
R–
E–
–EM
–SE
––
b2
b4
b6
b8
b10
b12
b14
b18
b16
b20**
b22**
b24
b26
b28
b30
b32
z4
z2
z6
z8
z10
z12
z14
z16
z18
z20**
z22**
z24
z26
z28
z30
z32
DI0
DO0
SLG transmit +
0 V
DI1
DO1
Select module (Select)
SLG receive –
SLG transmit –
0 V
Interface (type dependent)
24 V
Interface (type dependent)
()
Protective ground
(same as green LED)
()
Protective ground
MDS entry when EAKO=2
and EAKO=3***
free
MDS exit when EAKO=3***
free
ASM has user data or
acknowledgement (Request)
Error code (same as
red LED) Presence (ANW) ****
R+ (terminatingresistor) TxD (transmit data)
E+ (receive) RxD (receive data)
D+ (transmit) +EM (receive)
R– (terminating resistor) –EM (receive)
D– (transmit) +SE (transmit)
E– (receive) –SE (transmit)
* Pin b8 must not be connected in TTY mode!
** These data connections to the SLG are available as options on the backplane connector. They are identical to the
corresponding connections on the 9-pole submin. D connector.
*** EAKO = entry/exit checking (see chapter 5)
**** The presence of an MDS is indicated with 0 V level on this pin.

ASM 421 Technical Description6GT2 097-3AH00-0DA2
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Subject to change without notice! 6GT2 002-0DB00 ASM 421 / RS422
6GT2 002-0DC00 ASM 421 / TTY
J31069-D0142-U001-A0-7618
2.2.2 ASM 421 connector system
Connector: The connector used with the ASM 520 is a 48-way male connector conforming to DIN 41612
design F, whose soldering pins are bent through 90°. Rows z and b only are connected and
soldered directly to the ASM 520.
Socket: Female connectors conforming to DIN 41612 design F must be used as mating components
for the ASM 421 connector. In principle, all 48-way “female connectors conforming to
DIN 41612 design F” are suitable.
Various types of female connectors are available, e.g.:
– with solder terminations
– with a screw connection
– as a wire wrap version
e.g. SFL 0,5 / F 32 / 2 B:
10.5 23.6 14.8
Female connector with screw connec-
tion 0.5 mm2; rows z and b connected
zbd
Features:
– 3 rows of connectors
– Number of contacts: 32 (2 rows, each with 16 contacts)
– Contact principle: insulation displacement connector with double-sided contact spring
– Catch hooks and elements to ensure secure contact between male and female connectors

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2.3 Setting the mode of operation
Switch bank S1:
4532ON 1 7 86 ON
OFF
=^
=^
1 = Proximity message from ASM;
(Z-message)
0 = no proximity message
Access rights of this ASM station
00
01 Step “D” (= Delete); all commands allowed
10 Step “W” (= Write); Formatting of MDS and
deletion of files are not allowed
11 Step “R” (= Read only); only read operations on
the MDS are allowed
0 = Siemens file handler is set up
1 = reserved for 8-E41
1 = Master
0 = Slave
1 = odd parity
0 = even parity
Baud rate:
00 = 9600 Baud
01 = 4800 Baud
10 = Reserved for 38.4 KBaud
11 = 19200 Baud
Setting of the
3964R procedure
to the user
“1”
“0”

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2.4 Hardware planning
2.4.1 System configuration
SIEMENS
Computer/PC
RequestSelect
Serial
interface* DIDO
SIEMENS
SLG
read/write
device
SLG
read/write
device
The SLG read/write device can be connected to
either the X1 backplane connector or the 9-way
subminiature D connector X2.
one select line
for each
ASM 421
one request line
for each
ASM 421
serial
interface
PLC, PC
or
computer
Please note:
The Select and Re-
quest lines may be
omitted if only one
ASM 421 is being
driven from a serial in-
terface. The external
wiring of unnecessary
signals can also be
omitted.
* Daisy-chain confi-
gurations are only
possible with the
RS422 and TTY inter-
faces.
Two standard configurations
are available
– rack with 4 slots
– rack with 8 slots.

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ASM 421 interface modules can only be daisy-chained if they are using an RS422 or TTY interface. This
allows up to 16 interface modules to be driven from one serial interface.
The computer/PC must have a digital input (DI) and a digital output (DO) for each ASM 421.
Mode of operation:
Programming the ASM:
The computer/PC “selects” the module and then sends it the task telegram.
Command processing:
The ASM then processes the command. How long this takes depends on the command and can
last any amount of time (when there is no MDS in the field).
Send result to user:
By setting the “Request” flag, the ASM indicates that it wants to send a telegram. The computer/PC
recognizes this and “selects” the module. The selected ASM then sends the result telegram.
Task telegram
to ASM Response telegram from ASM
t2 t5 t4 t2 t1t3
Data
Request
Select
t1100 ms : Wait time from select until data transmission.
t20 : Wait time from data transmission until deselection of ASM 421
t3Depends on : Processing of user command by the ASM 421
command
t40 : Time from “request active“ until selection of ASM 421
** *
Select interrogate
t5= 0 ... 30 ms : Time from selection of the module until transmission of the result telegram
Important: * At the result telegram the ASM only interrogates the “select” at the beginning of a
transmission. If the “select” is deactivated during transmission of the telegram, the
ASM will nevertheless send the complete telegram to the computer.
This ensures that no garbled telegrams from the ASM are transmitted.
** The select line must be set high for the entire time that an outgoing telegram is being
sent.

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2.4.2 Power supply
The cable between the ASM 421 and the SLG read/write device is a 6-core shielded cable, of which 4
cores are dedicated to the data interface and 2 to the power supply for the SLG read/write device. The
maximum length of the data cables can, depending on the physical interface, be anything up to 1000 m.
The maximum permitted cable run is generally shorter if the 24 V supply for the SLG read/write device is
used by the ASM 421. The maximum cable length also depends on the level of voltage drop. The following
table gives an overview of permitted cable lengths:
Con-
ductor
dia.
[mm]
Resis-
tance
/km *)
SLG 40 / SLG 41
(I=90 mA) SLG 42 (I=180 mA)
Max. cable length when
UV= 30 V
0.3
0.5
0.8
1.0
1.4
550
185
70
50
24
120
360
950
1000
1000
240
720
1000
1000
1000
UV= 24 V UV= 30 V
40 100
120 300
310 790
440 1000
920 1000
SLG 43 (I=250 mA)
UV= 24 V UV= 30 V
30 70
85 210
230 570
320 800
660 1000
UV= 24 V
Max. cable length when Max. cable length when
SLG 44 (I=80 mA)
UV= 24 V UV= 30 V
90 200
250 650
700 1000
1000 1000
1000 1000
Max. cable length when
Con-
ductor
cross-
section
[mm2]
0.07
0.2
0.5
0.8
1.5
*) The values for resistance are average values and relate to the feed and return conductors. An individu-
al conductor has half the quoted resistance.
If cable runs longer than those specified in the table are used, the 24 V supply for the SLG read/write
device must not be used by the ASM 421. Instead, a 24 V supply must be fed directly to the SLG. (See
manual for configuration, installation and service; chapter 3.10; cable and connector allocation.)
Highlighted field:
The standard shielded LiYCY 6 x 0.25 cable recommended by SIEMENS. This cable is available from
SIEMENS under the order number 6GT2090-0A...1).
24 V supply to ASM 421:
The maximum length of the power supply cable for the ASM 421 is restricted to 20 m. If a longer cable is
used, or several ASMs are supplied from a single cable, the voltage drop on the supply cable to both
the ASM 421 and SLG read/write device must be taken into account. If necessary, the cross section of
the supply cable should be increased.
1) According to length code

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2.4.3 TTY cabling
TxD
RxD
max.
length
1000 m
+
+
TxD
RxD
ASM 421 (passive) Computer (active)
b4
z4
b6
z6
X1
–SE
+SE
–EM
+EM
X2
1–9
SLG
b30/
z30
The ASM module does not contain any power sources for energizing the active part of the TTY interface.
Should, however, it become necessary for the ASM to power the interface, the ASM should be wired as
follows to make it active:
TxD
RxD
max.
length
1000 m
TxD
RxD
RR
R
R
ASM 421 (active)
b4
z4
b6
z6
b32
z2
X1
Computer (passive)
X2
1–9
SLG
b30/
z30
The resistors R should each have a value of 470 Ohms to produce a current loop of 20 ... 30 mA
(P = 0.5 W).

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Example of a daisy-chain configuration (see 2.4.1)
CP
or
Computer
passive
+SE
–SE
+EM
–EM
4
7
0
+24 V
4
7
0
+24 V
active passive passive
.......
470
470
.......
** *
** *
dig.
inputs
*) This line must be looped through from the computer to the last ASM!
SLG
ASM 421 No. 1 ASM 421 No. 2 ASM 421 No. 4
b16
b4
b6 z6
z4 b4
b6 z6
z4
b4
b6
SLG SLG
z4
z4
b32
b32
Request
dig.
out–
puts
Select
z16 b16 z16 b16 z16
Where possible, the computer should handle the active part of the TTY interface, in which case the resis-
tors shown on ASM no. 1 will not be needed.
If this is not possible (as shown in the diagram), the active part of the interface must be simulated in the
connector of ASM no. 1 using 4 resistors (R = 470 Ohm).
The numbers in the diagram refer to pins in the 48-way female connector.
Note: With this cabling, all the wired ASMs must actually be connected, otherwise the circuit will
remain open!

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2.4.4 RS422 cabling
TxD
RxD
*) max.
length
1000 m
ASM 421 Computer
X2
1–9
SLG
b4
z4
b6
b8
z6
z8
X1
*) E–
D–
D+
E+
b30/
z30
+5V
**)
**)
*) The cable can be terminated on the receiving side with jumpers z4 – b4 and z8 – z6. This improves the interference immunity of
the system particularly when long cables are used (i.e., > 200 m). The jumpers may only be wired on the last ASM 421 when daisy
chain operation is used (see chapter 2.4.1).
**) The indicated terminal resistors (R = 200 to 1000 Ohm) must be present on the computer side. These resistors can be wired on
the ASM side when short cables are used. This means jumpers z6 – z8 and b4 – z4 are omitted and 2 jumpers are added
(i.e., b4 – b6 and z6 – b8).
Example of a daisy-chain configuration (see 2.4.1)
CP
or
computer
+E
–E
+D
–D
.......
.......
Enable Enable Enable
dig.
inputs
SLG
ASM No. 1 ASM No. 2 ASM No. 4
SLG SLG
z4
z8 z4 z8 z4 z8 z4 z8
b6
b8 b6 b8 b6 b8 b6 b8
b16 b16 b16
dig.
out–
puts
Request
Select
z16
max. 1000 m
z16
z16

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2.4.5 V.24 cabling
TxD
RxD
TxD
RxD
ASM 421 Computer
max.
length
30 m
b32
b6
z4
X2
1–9
SLG
X1
b30/
z30
V.24 control lines (e.g. DSR, DTR, RTS, CTS) are not supported by the ASM. The acknowledgement of
data is handled by the procedure.
2.4.6 STG cabling
TxD
RxD 1
9
+
ASM 421 STG 4F
Test cable
length max.
100 m
E–
D–
D+
E+
X1
z2
z8
b8
b6
z4
b320V
X2
1–9
SLG
24 V b30/
z30
z6
b4
The ASM 421 / RS422 can be operated directly with the STG 4F. The complete path from the STG 4F via
the ASM 421 to the SLG will thus be tested.

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2.4.7 DI/DO cabling
Cable length
max. 100 m
(shielded or unshielded)
220 V
24 V=
ANW
Error code
DI 1
DI 0
Imax = 200 mA
(per DO or
Proximity switch+–
total current)
ASM 421
z2
z18
b18
z12
b12
b2
Relay (use break-contact
in load circuit of relay),
horn, lamps, etc.

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3 Programming the ASM 421 module
3.1 3964R procedure
The 3964R procedure provides secure data transmission across a point-to-point connection. Security is
achieved by transmitting the data one block at a time with parity check, block check character (BCC) and
acknowledgement of receipt. All characters from 00hex to FFhex can be present in the data block.
Character frame:
Transmission: asynchronous
Baud rate: 2400, 4800, 9600, 19200 Baud
Data bits: 8
Parity: odd/even (switch selectable)
Stop bit: 1
12345678P
8 data bits
Start step Parity bit
Stop bit
Character frame 11 bits Start step
Next
character
t
Control characters in the 3964R procedure:
Character Code (hex) Purpose
STX
DLE ETX
DLE
NAK
DLE DLE
02
10 03
10
15
10 10
Initialization of a transmit operation (signals ready–to–send)
Marks the end of a transmission block
Ready–to–receive (or DLE duplication in data stream)
Negative response on block–check–error or unrecognized
DLE duplication in data block; used if the value 10hex
occurs in the data stream.
start character