This will do what you are asking (although a GDEV is better) BI01 = the .BAD parameter BI02 = the .CIN of the OPEN state BI03 = the .CIN of the CLOSED state any travel timing issues are left as an exercise for the reader. TEST_FCP:VLV_STAT TYPE = CALCA DESCRP = SET VLV STATES STEP01 = IN BI01 ; BAD BLOCK STEP02 = IN 100 ; STEP03 = MUL ; MULTIPLY BY 100 STEP04 = IN BI02 ; OPEN BIT STEP05 = IN 10 ; MULTIPLY BY 10 STEP06 = MUL ; STEP07 = IN BI03 ; CLOSED BIT STEP08 = IN 20 ; STEP09 = MUL ; MULTIPLY BY 20 STEP10 = ADD 3 ; STEP11 = OUT RO01; 0=BOTH CLOSED STEP12 = ; 10 = OPEN STEP13 = ; 20 = CLOSED STEP14 = ; 30 = BOTH LIMITS MADE STEP15 = ; >30 = BAD END Later, David Confidentiality Notice: The information contained in this message is private and confidential. This information is intended only for the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any use, review, dissemination, distribution, copying or action taken based on this message or its attachments, if any, is strictly prohibited. If you are not the intended recipient, please contact the sender by reply email and delete or destroy all copies of this message and any attachments. Thank you. _______________________________________________________________________ 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