M20 Diagnostics - Siemens M20 Terminal Technical Description

Siemens Information and Communication Products
8.3

M20 diagnostics

The following AT commands can be used to query information for diagnostics:
• AT+CSQ Signal quality (receive level)
This command with the corresponding parameters can be used to query the reception level in dBm and the bit error
rate (RXQUAL) as per GSM Rec. GSM 05.08, Section 8.2.4.
• AT+CREG – Network status
This command can be used to query the network status. The messages can be, for example, "not registered, currently
searching for a network", "registered", "registration denied", etc. as answers to this command.
• AT+CREG? +CREG: <n>, <stat>[,<lai>,<ci>]
This command combination can be used to query the Location Area Identifier (lai) and the Cell ID (ci).
These AT commands are described in more detail in Section
Other diagnostics:
Sending AT<CR> tests the interface between the base unit and the M20. If the M20 responds with OK, the interface is
basically in full working order.
Information on the status or operation of the antenna is not possible because the RF field at the local site determines the
result of any function query. If there is reason to suspect that poor reception or lack of reception is due to a defective an-
tenna, this is easily checked by connecting a reference antenna. Alternatively, the antenna could be checked separately
with the aid of a voltage standing wave ratio meter (VSWR meter).
8.3.1 Basics
No Fault Error
Message
1 System Booting not
possible
2
3 System Booting not
possible
4
Version 8 dated 15.03.00
5.1 "Syntax of the standard AT commands" on page 27
Status Check
Power connected, Power supply plugged in, Volta-
Ignition high for ge available on 6 pole Western
1 second. no sy- plug
stem reaction to
booting
procedure, LED
stays OFF
M20T
fuses blown
M20: Power con- Ignition is set to high for at least
nected, even if 1 second
Ignition is set no
reaction
Bootcode is set high. (only
allowed for SW downloading)
M20 plugged into 80 pole wrong
way round. Pin 80 with pin41.
Power connected, Power supply plugged in, Volta-
Ignition high for ge available on 6 pole Western
1 second no sy- plug
stem reaction to
booting
procedure, LED
stays OFF
M20T
fuses blown
Application notes
SW response / Action
comment
Check all power connec-
tions / test for
voltages.
Check ignition key
Disconnect Bootcode
from High
Connect M20 other way
round
Check all power connec-
tions / test for
voltages.
Replace M20T fuse:
SMD fuse white (mar-
ked "12"), next to 6 pole
western Plug
A
.
174