Cable Spec 41 - NULL MODEM Crossover DB9 to DB25 Pinout
Written by Michael Cone
Updated at January 26th, 2026
This pinout is the null modem standard that works with all MiiC benders that use the MiiC BSC protocol.
If you purchase a pre-made null-modem cable, it will most likely contain this pinout schematic. A purchased cable may also contain DB9 pin 9 to DB25 pin 22 RI - "ring indicator". Since the RJ45 adapters have eight wires, it is necessary to omit this last connection.
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