Programming in PLC

[Guest irfan]

See attachment !!! txt file,... ladderlogic.txt

[Steve Bailey]

The 90-30 does not support programming that requires accessing %R addresses at the bit level, which is what you're trying to do in your second rung. LM90-30 won't let you enter a rung like that. Even if it did, your addressing would have to be something like %R0001.01 or %R0001/02, not as you've presented it. %R0001 is a 16-bit address. %R0002 is the next consecutive 16-bit address, not the second bit. I don't know why you don't just use the %I and %Q addresses directly in your program instead of the MOVE instructions, but if you're determined to do it that way, MOVE the %I addresses to %M. A MOVE_INT instruction with %I0001 on the left side of the function, %M0001 on the right side, and the LEN = 1 will move %I0001 to %M0001, %I0002 to %M0002, ....... %I0016 to %M0016.

[JimRowell]

Like Steve says, you're making it more complex than it needs to be. With a Mitsubishi, I'd do it like this: ;Both level sensors should be of a type where they ; close their contacts when liquid is NOT present. ;Fill'Valve will pass liquid when energised. ;Mitsubishi version. LD LOW'LEVEL ;low-level start signal from input. SET FILL'VALVE ;directly set the output (turn it on). LDI /HI'LEVEL ;"not-high-level" enable signal (high-level stop signal from input). RST FILL'VALVE ;turn off the output. It's been a while since I used any Allen Bradley but I believe it would translate like this: XIC LOW'LEVEL ;low-level start signal from input. OTL FILL'VALVE ;directly set the output (turn it on). XIO /HI'LEVEL ;"not-high-level" enable signal (high-level stop signal from input). OTU FILL'VALVE ;turn off the output. Jim Rowell

[JimRowell]

OOPS! I just realized I'm in the GE forum (not AB). Sorry about that! <grin> Anway, the examples should give you an idea. Jim

[Guest irfan]

Thanks, Steve,.. I have a better view about PLC programming in Series 90-30 now,.. You just explain in your previous answer that %R data type is 16 bit. By the way,.. Can you show me the data type of each address below? because I can't find it in the manual "gfk467m.pdf" which explain the data type of these address directly. Flow, %I, %Q, %M, %T, %S, %G, %R, %AI, %AQ. I don't use %I and %Q directly to keep data in PLC when %I and %Q change state. Is it right ? And about MOVE_INT instruction data type : I think if we put %I0001 on the left side with LEN=1 and %M0001 on the right side it will only move 1 data %I to 1 data %M : %I0001 to %M0001 For LEN=2 If we put %I0001 on the left side and %M0001 on the right side It will only move 2 data %I to 2 data %M : %I0001 to %M0001 %I0002 to %M0002 For LEN=3 If we put %I0001 on the left side and %M0001 on the right side It will only move 3 data %I to 3 data %M : %I0001 to %M0001 %I0002 to %M0002 %I0003 to %M0003 and so on,...... Thanks again,.. Irfan Edited March 8, 2004 by irfan

[Steve Bailey]

%I, %Q, %M, %G, %S, %T are discrete (On/Off) data types. %R, %AI, %AQ are 16-bit registers. These are all covered in Chapter 2 of GFK-0467m, starting on page 2-20. When you use the MOVE_BIT instruction, it behaves as per your expectations. The LEN parameter refers to the number of bits. When you use the MOVE_INT instruction, the LEN parameter refers to the number of 16-bit integers. When you use Logicmaster software and select a MOVE instruction, the default data type is INT. You have to change it to BIT, DINT, or REAL. When using VersaPro or CME software, you select either MOVE_INT, MOVE_DINT, MOVE_REAL, or MOVE_BIT from a list.