User's Manual

General Document, Register Cobra module on CMU200
Author: Version:
V01
–
F1
Creation Date:
Jul 31, 2006
Page:
4 of 6
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Option NV.
2.2 Settings on the module
When previous steps didn’t do the trick, please check the settings on the card.
All steps mentioned next, should be evaluated in this order.
After each step, perform a safe removal of the card.
1. At_opbm
When not working in a shielded environment, all life networks could interfere with the signal
coming from the CMU. When the simulated network is not in the same band as the surrounding
life networks, this problem can be avoided by deselecting all other basebands but the one you are
working in.
This could be done using the at_opbm command:
Extract from datasheet:
Preferred Band Mode _OPBM
Command Possible response(s)
_OPBM=<band>,<n> OK
_ OPBM =? _OPBM: (list of supported <band>s)
_ OPBM? <band>: <n>[<CR><LF><band>: <n>[…]]
Description
This command is used to disable/enable specific frequency bands.
Defined Values
<band>
“ANY” : any band
“EGSM” : EGSM (900MHz) band
”DCS” : DCS (1800MHz) band
”PCS” : PCS (1900MHz) band
”G850” : GSM 850MHz band
”U2100” : WCDMA 2100MHz band
”U1900” : WCDMA 1900MHz band
“U1700”
“U17IV”
“U850” : WCDMA 1900MHz band
<n>
0 : disable
1 : enable
Eg: if you use GSM1900 (PCS) band, select only this band. All other bands have to be deselected.
It is also very important to deselect EVERY UMTS band when trying to connect to a GSM
network and vice versa: