116
Address Instruction Data
0007 AND NOT 0003
0008 LD 0004
0009 AND 0005
0010 OR 0006
0011 AND LD ––
0012 OUT 0505
Address Instruction Data
0000 LD 0000
0001 AND 0001
0002 LD 0100
0003 AND 0101
0004 OR LD ––
0005 OR 0500
0006 AND 0002
7–2–4 Coding Other Instructions
When combining other right-hand instructions with ladder diagram instruc-
tions, they would appear in the same place as the OUTs used in the example
in the preceding section. Many of these instructions, however, require more
than one word to code.
The first word of any instruction defines the instruction and provides any de-
finers and sometimes bit operands required by the instruction. All other oper-
ands (i.e., operand words) are placed in words after the instruction word, one
operand to a word, in the same order as these appear in the ladder symbol
for the instruction. Although the SV for TIM and CNT are written to the left of
the symbol on the same line as the instruction, these are the only instructions
for which one line in the ladder symbol must be coded as two words (i.e., two
lines) in the mnemonic code. Also the TC number for TIMH(15) is placed on
a second line even though it is part of the instruction word. For all other in-
structions, each line of the ladder diagram will go into one word of mnemonic
code.
The address and instruction columns of the mnemonic code table are filled in
for the instruction word only. For all other words, the left two columns are left
blank. If the instruction word requires no definer or bit operand, the data col-
umn for it is left blank. It is a good idea to cross though the blank data col-
umn for all instruction words not requiring data so that the data column can
be quickly scanned to see if any addresses have been left out.
If an IR or SR address is used in the data column, the left side of the column
is left blank. If any other data area is used, the data area abbreviation is
placed on the left side and the address is place on the right side. If a con-
stant is to be input, the number symbol (#) is placed on the left side of the
data column and the number to be input is placed on the right side. Any num-
bers input as definers in the instruction word do not require the number sym-
bol on the right side. Remember, TR bits, once defined as a timer or counter,
take a TIM (timer) or CNT (counter) prefix.
When coding an instruction that has a function code, be sure to write in the
function code, which will be necessary when inputting the instruction.
The following diagram and corresponding mnemonic code illustrate the
points described above.
Converting to Mnemonic Code Section 7–2
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