Rockwell Studio 5000

Logix Designer, RSLogix 500/5000, RSLinx, FactoryTalk and the faults you meet on a ControlLogix or CompactLogix line.

JSR, SBR and RET: Passing Parameters Into a Routine Without a Controller Tag

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A diagram of one JSR call: the calling routine's program-scoped tags on the left, the JSR instruction with two input parameters and one return parameter in the middle, the subroutine's own program-scoped tags on the right, and a numbered list of the five steps from rung true to RET copying the answer back

JSR, SBR and RET: Passing Parameters Into a Routine Without a Controller Tag Type 4, Code 31 on a 1756-L83E, and the routine it pointed at was three rungs long. The general instructions reference gives three separate ways to earn that code and every one of them is about counting: a JSR with fewer input … Read more

The MSG Control Tag on a Logix Controller: What Each Tab Writes Into It

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Three columns headed Configuration, Communication and Tag, each listing the fields on that tab of the Message Configuration dialog next to the MESSAGE structure member the field is stored in, with a note that configuring the message once configures every rung naming the same tag

The MSG Control Tag on a Logix Controller: What Each Tab Writes Into It Line_Msg.DN came true on rung 13 of a 1756-L71 and the forty DINTs the rung was guarding still held last shift’s numbers. The bit had been set by a different message — a four-element write to a capper down on rung … Read more

COP and CPS Instructions on a ControlLogix: Which One Copies What

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Worked byte arithmetic for a COP with Length 20 from a five-element SINT array into a ten-element DINT array: the source drawn as five one-byte cells, the destination as ten four-byte cells, then the three limits stacked as requested 80 bytes, destination tag 40 bytes and source tag 5 bytes, with the five-byte answer boxed

COP and CPS Instructions on a ControlLogix: Which One Copies What A COP with a Length of 20 moved five bytes. The source was Packer_Raw, a SINT[5]; the destination was Packer_Scaled, a DINT[10]; the rung went true on every scan of a 1756-L71 and nothing faulted, nothing latched, nothing appeared in the Minor Faults tab. … Read more

The First Scan Bit in Studio 5000: What S:FS Is For, and What It Must Never Do

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Three stages across one transition to Run mode: prescan with outputs cleared, timers reset and inputs not current; the first normal scan with S:FS true for that one scan; and every later scan with S:FS false, annotated with what each stage resets

The bagger came back with 0.0 in every recipe setpoint at 06:10, with nobody at the HMI and no download on the log. The only change on that shift was a program that had been inhibited while somebody edited it and then put back in, and the initialisation rung inside it — one XIC on … Read more

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