The correct full command line should have been:

find * -type f \( -name "*.pm" -or -name "*.pl" -or -name "*.tst" -or -name "*.cfg" -or -name "*.vhd" -or -name "*.psl" -or -name "*.do" \) -print0 | parallel -q -0 sed -i -e 's/FAULT_DETECT_/FD_/g;s/RESET_/RST_/g;s/TRIGGER_/TRIG_/g;s/INSTRUMENTATION_/INST_/g;s/IMPLEMENTATION_/IMPL_/g;s/_DURATION/_DUR/g;s/_ACTIVE/_ACT/g;s/_CONFIG/_CFG/g;s/OPTIMIZATION_OFF/OPT_OFF/g;s/s_fiji_trigger_/s_fiji_trig_/g'