GPIB 'Multidevice' API timeout

I'm using the GPIB 'multidevice' API for a project, but I find that
the default command timeout is much too long to wait. Typically, using
the 'traditional' API, I would set the timeout using the ibdev()
command when I first initialize the GPIB device. But, since I'm using
this 'multidevice' API, that isn't an option.
Does anybody know a GPIB command other than ibdev() that sets the bus
timeout?

Thanks,
PaulH

.