• Table of contents
• Siemens GSM-R CAB Radio
  • Sub-Rack Hardware
    • Backplane
    • High Voltage Power Supply Module
    • 12V -> 5V DC/DC converter Module
    • GSM Modem Module
      • Digital Board
      • RF Board
    • PC/104 embedded PC Module
      • Carrier
      • PC/104 x86 SBC
    • I/O board
    • Audio PA + Relay board
    • Frontplane
  • Handset Hardware
    • Internal Pictures
  • Connector pinout
    • EXT RADIO (DB-15 female)
    • SER I/O (DB-25 male)
    • HMI 1 (DB-25 female)
    • HMI 2 (DB-25 female)
    • MVB OUT (DB-9 female)
    • MVB IN (DB-9 female)
    • ANT (N)
    • PMU (DB-9 male)
    • TRAIN POWER AND I/O (circular connector)

Siemens GSM-R CAB Radio¶

Osmocom has been provided with two ancient Siemens GSM CAB Radio devices, i.e. the kind of MS installed fixed into a train engine.

Sub-Rack Hardware¶

Backplane¶

At the back of the sub-rack there's a custom back-plane to interconnect the various modules

High Voltage Power Supply Module¶

This is a fully encapsulated, passive cooled, DC/DC converter with

• Input voltage 65..150V
• Two output voltage rails of 12V / 4A

12V -> 5V DC/DC converter Module¶

This is a circuit board that generates a 5V rail from 12V

GSM Modem Module¶

This is a module implementing the actual GSM-R modem. It consts of two circuit boards: One digital and one analog/RF.

Digital Board¶

RF Board¶

PC/104 embedded PC Module¶

This is a carrier board hosting a PC/104 embedded x86 Mainboard.

Carrier¶

We can see this carrier interfacing with

• the 8-bit lower portion of the ISA bus on the PC/104 connector (J40)
• COM1 (J4)
• COM2 (J41)
• COM3 (J50)
• COM4 (J49)
• Utility (J27) Mouse/Keyboard/Reset/Speaker

PC/104 x86 SBC¶

This is a swiss-made Digital-Logic MSM586SEV.

• 586 compatible processor (AMD ELAN520) @ 133 MHz
  • ELAN520 data sheet: 22004b.pdf
• 32 MByte SO-DIMM memory
• 16 MByte M-Systems DiskOnChip MD-2202-D16
• 4x UART / COM port
• 1x parallel port
• 1x RTC
• AT-keyboard, PS/2, Floppy, IDE interface
• PC/104 bus

Resources:

• Data sheet: Microspace_Digital_Logic_MSM586SEN_Datasheet2_201872793522.pdf
• Manual: Microspace_Digital_Logic_MSM586SEN_Manual_201872793522.pdf

I/O board¶

This is a board that brings signals from the backplane and frontplane and brings them to connectors towards the main connector panel.

We can see a number of SRDA05-6 TVS diode arrays as ESD protection measure, as well as some Datatronic LM201-1 signal transformers.

Audio PA + Relay board¶

This board appears to contain an audio Power Amplifier

Frontplane¶

There's a board on the front side of the unit which interconnects the I/O board and the Relay / Audio PA board.

Handset Hardware¶

The specific handset unit here was used for demo purposes ourside an actual train cab. So the auto-radio-looking user interface unit plus the receiver were mounted together with a 230V AC -> 110V DC power supply in an enclosure that you can connect to the subrack via two cables.

Internal Pictures¶

Connector pinout¶

EXT RADIO (DB-15 female)¶

SER I/O (DB-25 male)¶

HMI 1 (DB-25 female)¶

This is the connector used to interconnect with the User Interface unit. HMI most likely means Human Machine Interface.

HMI 2 (DB-25 female)¶

MVB OUT (DB-9 female)¶

This is internally wired 1:1 with the MVB IN connector. It likely contains an interface to the Multifunction Vehicle Bus of the train.

See https://en.wikipedia.org/wiki/Train_communication_network for details on MVB.

MVB IN (DB-9 female)¶

ANT (N)¶

This a standdard 50-ohms N-type conector to connect to the GSM-R antenna.

PMU (DB-9 male)¶

This connector is forwarded internally to the DB-9 connector on the front of the embedded PC. Probably serial console.

TRAIN POWER AND I/O (circular connector)¶

Pin (ext)	Internal Connector	Internal Connector Pin	Wire color	Purpose
H	PL6	1	rose
K	PL6	2	white
M	PL6	3	green
P	PL6	4	purple
S	PL6	5	blue
J	PL6	6	black
L	PL6	7	red
N	PL6	8	yellow
R	PL6	9	orange
B	PL6	10	green
T	PL7	1	white
d	PL7	2	green
F	PL7	4	blue
A	PL7	5	red
U	PL7	6	rose
e	PL7	7	blue
G	PL7	9	grey
C	PL7	10	yellow
V	PL8	1	white
D	PL8	3	purple
W	PL8	4	red
E	PL8	6	orange
c	PL9	1	orange
Z	PL9	2	rose
X	PL9	3	green
b	PL9	4	grey
a	PL9	5	red
Y	PL9	6	yellow