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Download Logicmaster 90-70 Programming Software User's Manual, GFK
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3 Formal Parameters within a Parameterized Subroutine Block In general, formal BIT parameters are allowed on all contacts, coils, and function block parameters that allow discrete references (%I, %Q, %M, %T, %S, %G, and %U). Formal WORD and NWORD parameters are allowed on all function block parameters that allow register references (%R, %AI, %AQ, %P, %L, and %UR). However, the list provided on the next page contains several exceptions and restrictions. Note NWORDs are used only with Parameterized Subroutine Blocks. NWORDs allow an array of words to be referenced. NWORD parameters enforce type checking for DWORD, DINT, and REAL instructions. To avoid confusion, please read the explanation presented below. NWORDs Defined An NWORD is a number of words passed into and/or out of a Parameterized Subroutine Block. NWORDs can be treated as WORDs or DWORDs, determined by the way they are accessed. If you are using DWORD/DINT features, such as MATH or MOVE, you must set up the array as shown at the bottom of this page. NWORD parameters are parameters that make up multiple WORDs; i.e., NWORD parameters comprise an array of WORDs. The size of NWORDs is specified in WORDs, not DWORDs. NWORD parameters may be used on any multi-word operands, but NOT on discrete type parameters. When to Use NWORD Parameters Rather Than WORD Parameters If you are using floating point math or if your Parameterized Subroutine Block (PSB) function requires multi-WORD-oriented reference types, use NWORD parameters. WORD parameters allow discrete references (e.g., %I, %Q, etc.); NWORD parameters do not allow discrete references. Using NWORDs Within a Parameterized Subroutine Block, the first word of an NWORD parameter would be referenced by X1[1], for example. The second word would be referenced by X1[2], etc. If you want to pass DWORD parameters into a Parameterized Subroutine Block, you must use the NWORD parameter type. The first DWORD would be referenced by X1[1] (same as for word). However, the second DWORD would be referenced by X1[3]; the third by X1[5], etc. NWORD NWORD NWORD NWORD NWORD NWORD 3-98 Parm X1[1] Parm X1[2] Parm X1[3] Parm X1[4] Parm X1[5] Parm X1[6] Logicmaster First WORD First DWORD Second WORD Third WORD Second DWORD Fourth WORD Fifth WORD Third DWORD Sixth WORD t 90-70Programming Software User’s Manual – June 1998 GFK-0263G
