How can I read out several variables at once?
You can do this in two steps.
ask for offsets and length of the variables
pi@RevPi99988:~ $ piTest -d
Found 1 devices:
Address: 0 module type: 136 (0x88) RevPi Connect 4 V1.0
Module is present
input offset: 0 length: 6
output offset: 6 length: 7
then output them - here we read out all inputs of the RevPi Connect 4
pi@RevPi99988:~ $ piTest -1 -r 0,6,h 01 00 00 00 2d 96