Set the target type first and it will probe for suitable BDMs and list them with the BDM number.
e.g.
USBDMScript incorporating TCL - Copyright(c) 2011
Press ? for help
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usbdm_rc.tcl
================
This file is 'sourced' whenever usbdmScript.exe is executed
Add your own custom commands
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% settarget arm
USBDM DLL Version = 4.12.1.150
BDM List:
0 - USBDM-OPENSDA-3230891 : USBDM ARM-SWD for OpenSDA
Found 1 devices
:setTarget ARM
% openbdm 0
Opening USBDM-OPENSDA-3230891
BDM Version = HW=59, SW=4C
% connect
:connect
% reset
:reset 0x1C(DEFAULT, SPECIAL)
% regs
regs
R0 => 00000000, R1 => 00000000, R2 => 00000000, R3 => 00000000,
R4 => 00000000, R5 => 00000000, R6 => FFFFFFFF, R7 => 20002FF8,
R8 => FFFEFFFF, R9 => FFFFFFFF, R10 => 1FFF3000, R11 => 00000000,
R12 => 00000000, SP => 20003000, LR => 00003647, PC => 000004E8,
PSR => 41000000, MSP => 20003000, PSP => FFFFFFFC,
FPSCR => 00000000, CONTROL/FAULTMASK/BASEPRI/PRIMASK => 00000000,
PC = 0x000004E8 : 0x02F0 0xF0FA
% rb 0 100
:rb =>
0x00000000 : 00 30 00 20 E9 04 00 00 0D 2B 00 00 25 2B 00 00
0x00000010 : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x00000020 : 00 00 00 00 00 00 00 00 00 00 00 00 0D 2B 00 00
0x00000030 : 00 00 00 00 00 00 00 00 0D 2B 00 00 0D 2B 00 00
0x00000040 : 0D 2B 00 00 0D 2B 00 00 0D 2B 00 00 0D 2B 00 00
0x00000050 : 0D 2B 00 00 0D 2B 00 00 0D 2B 00 00 0D 2B 00 00
0x00000060 : 0D 2B 00 00
0
%