Allen-Bradley MicroLogix 1200 Reference Manual page 359

Execution Times for the Indirect Addresses
For most types of instructions that contain an indirect address(es), look up
the form of the indirect address in the table below and add that time to
the execution time of the instruction.
[*] indicates that an indirect reference is substituted.
Table B.2 MicroLogix 1500 Controllers
Instruction Execution Time Using Indirect Addressing
Address Operand
Form Time (µs)
O:1.[*] 4.8
O:[*].0 12.3
O:[*].[*] 12.4
B3:[*] 4.8
B[*]:1 19.9
B[*]:[*] 20.1
L8:[*] 5.2
L[*]:1 20.4
L[*]:[*] 20.1
T4:[*] 4.9
T[*]:1 19.7
T[*]:[*] 19.8
T4:[*].ACC 5.1
T[*]:1.ACC 19.9
T[*]:[*].ACC 20.5
O:1.[*]/2 5.4
O:[*].0/2 12.8
Execution Time Example – Word Level Instruction Using an Indirect Address
ADD Instruction Addressing
Source A: N7:[*]
Source B: T4:[*].ACC
Destination: N[*]:[*]
Execution Time Example – Bit Instruction Using an Indirect Address
XIC B3/[*]
• XIC: 0.9 µ s + 4.8 µ s = 5.7 µ s True case
• XIC: 0.0 µ s + 4.8 µ s = 4.8 µ s False case
MicroLogix 1500 Memory Usage and Instruction Execution Time
Address Operand
Form Time (µs)
O:[*].[*]/2 13.3
O:1.0/[*] 5.9
O:1.[*]/[*] 6.5
O:[*].0/[*] 14.1
O:[*].[*]/[*] 14.5
B3:[*]/2 5.4
B[*]:1/2 20.4
B[*]:[*]/2 21.0
B3:1/[*] 5.9
B3:[*]/[*] 6.5
B[*]:1/[*] 21.6
B[*]:[*]/[*] 22.3
L8:[*]/2 5.5
L[*]:1/2 20.4
L[*]:[*]/2 21.0
L8:1/[*] 5.9
L8:[*]/[*] 6.5
ADD Instruction Times
ADD Instruction: 2.5 µs
Source A: 4.8 µ s
Source B: 5.1 µ s
Destination: 20.1 µ s
Total = 32.5 µ s
B-5
Address Operand
Form Time (µs)
L[*]:1/[*] 21.6
L[*]:[*]/[*] 21.9
T4:[*]/DN 5.7
T[*]:1/DN 20.4
T[*]:[*]/DN 20.7
T4:[*].ACC/2 6.4
T[*]:1.ACC/2 20.4
T[*]:[*].ACC/2 21.6
T4:1/[*] 5.9
T4:[*]/[*] 7.1
T[*]:1/[*] 21.8
T[*]:[*]/[*] 22.4
T4:1.ACC/[*] 6.0
T4:[*].ACC/[*] 7.5
T[*]:1.ACC/[*] 21.8
T[*]:[*].ACC/[*] 22.9
Publication 1762-RM001C-EN-P