描述
為監(jiān)控PLC運行程序是否正常,PLC系統(tǒng)都設(shè)置了”看門狗”(Watchingdog)監(jiān)控程序。運行用戶程序開始時,先清”看門狗”定時器,并開始計時。當(dāng)用戶程序一個循環(huán)運行完了,則查看定時器的計時值。若超時(一般不超過100ms),則報警。嚴(yán)重超時,還可使PLC停止工作。用戶可依報警信號采取相應(yīng)的應(yīng)急措施。定時器的計時值若不超時,則重復(fù)起始的過程,PLC將正常工作。顯然,有了這個”看門狗”監(jiān)控程序,可保證PLC用戶程序的正常運行,可避免出現(xiàn)”死循環(huán)”而影響其工作的可靠性。
ABB Robotics Control DSQC230 DSQC-230
ABB DSQC-252 3HAA 3563-ALA/2 PC Board
ABB Converter Card Robot Control DSQC 129 #13986
ABB DSQC 224 I/O Board
ABB DSQC 224 COMBINATION I/O MODULE ***XLNT***
ABB DSQC 230 YB560103-BN PC BOARD
ABB DSQC 336 Ethernet board 3HNE 00001-1
ABB SERVO DRIVE UNIT R3HAB8802 DSQC 266T ~ Used
ABB AB DSQC 266T 266 DSQC266T 3HAB8802-1/2B ACC49M029AB
One-day shipping available
ABB DSQC 236C YB560103-CC SERVO POWER UNIT *
ABB YB161102-AD DSQC103 S2 R/D Exciter Board