PLB's were occasionally useful back in the CP10 days to offload some of the processing duty from the CP down to the FBM. You had to ration your CALC blocks pretty carefully back then. I haven't used one since we got our first CP30. Greg Hurwitt BASF Freeport |---------+------------------------+----------------------------> | | |Corey R Clingo | | | |<clingoc@xxxxxxxxxxxxx> | | | |Sent by: | | | |foxboro-bounce@xxxxxxxxxxxxx| | | | | | | | | | | |05/12/05 09:58 AM | | | |Please respond to foxboro | | | | | |---------+------------------------+----------------------------> >---------------------------------------------------------------------------------------------------------------| | To: foxboro | | cc: | | Subject: Re: [foxboro] Reduce IFL's for FBM | >---------------------------------------------------------------------------------------------------------------| |---------+------------------------+----------------------------> | | | | |---------+------------------------+----------------------------> >---------------------------------------------------------------------------------------------------------------| | | >---------------------------------------------------------------------------------------------------------------| This has been an interesting discussion. I've personally never used PLBs, because I didn't need the processing speed that they give (in truth, I'm not sure it's really any faster, but I presume the FBM processes logic at a somewhat greater rate than the CP), and I try to avoid YAT (Yet Another Tool) unless the benefit warrants it. But I've never needed PLBs, either; CALCA/LOGIC blocks, CINs, COUTs, and GDEVs provide all the tools I have ever needed for discrete interlocks. And locking of appropriate parameters (via connection to themselves or other blocks) provides adequate protection from changes (though I still would like to see a system-wide security mechanism, enforced at the CP level). Corey Clingo BASF Corp. _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave _______________________________________________________________________ This mailing list is neither sponsored nor endorsed by Invensys Process Systems (formerly The Foxboro Company). Use the info you obtain here at your own risks. Read http://www.thecassandraproject.org/disclaimer.html foxboro mailing list: //www.freelists.org/list/foxboro to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave