Max/Min (0BA7 and later versions only)

Short description

The Max/Min function block records the maximum or minimum value.

LOGO! 9 and later versions support two data types: integer (16-bit) and float (32-bit).

Connection

Description

Input En

The function of input En (Enable) depends on the settings of parameter Mode and the selection of check box "when En = 0, reset Max/Min".

Input S1

This input is enabled when you set Mode =2:

A positive transition (0 to 1) at input S1 sets the output AQ to the maximum value.

A negative transition (1 to 0) at input S1 sets the output AQ to the minimum value.

Input Ax

Input Ax is one of the following analog signals (integer or float):

  • AI 1:

    • LOGO! 9: AI1 to AI16 3

    • 0BA8: AI1 to AI8 4

  • AM 1:

    • LOGO! 9: AM1 to AM128

    • 0BA8: AM1 to AM64

    • 0BA7: AM1 to AM16

    • 0BA6: AM1 to AM6

  • NAI 1:

    • LOGO! 9: NAI1 to NAI128

    • 0BA7 or 0BA8: NAI1 to NAI32

  • AQ 1:

    • LOGO! 9: AQ1 to AQ16

    • 0BA8: AQ1 to AQ8

    • 0BA7: AQ1 and AQ2

  • NFAI 2:

    • LOGO! 9: NFAI1 to NFAI16

  • FAM 2:

    • LOGO! 9: FAM1 to FAM32

  • The block number of a function with analog output 1 2

Parameter

Mode

Possible settings: 0, 1, 2, 3

Mode = 0: AQ = Min

Mode = 1: AQ = Max

Mode = 2 and S1= 0 (low): AQ = Min

Mode = 2 and S1= 1 (high): AQ = Max

Mode = 3 or a block value is referenced: AQ = Ax

Output AQ

AQ outputs a minimum, maximum, or actual value depending on the inputs, or is reset to 0 if configured to do so when function is disabled

1 If the data type of Ax is integer and the data type of this FB is configured as float, LSC will convert Ax into 32-bit receivable float data.

2 If the data type of Ax is float and the data type of this FB is configured as integer, LSC will cut off the decimal numbers of Ax and convert it into 16-bit receivable integer data.

3 AI1 to AI16: 0 to 10 V corresponds with 0 to 1000, 0 to 4095 or 0 to 10000 (internal value).

4 AI1 to AI8: 0 to 10 V corresponds with 0 to 1000 (internal value).

Parameter Mode

You can set the values for parameter Mode based on the actual values of another already-programmed function:

For the 0BA8 and later version devices, you can additionally use the actual values of the following already-programmed functions:

For the LOGO! 9 and later version devices, you can additionally use the actual values of the following already-programmed functions:

You can select the required function by the block number.

Timing diagram

*) If you select the check box "when En = 0, reset Max/Min"

Description of the function

If you select the check box "when Enable = 0, reset Max/Min":

If you do not select the check box "when Enable = 0, reset Max/Min":

Mode = 0: The function sets AQ to the minimum value

Mode = 1: The function sets AQ to the maximum value

Mode = 2 and S1 = 0: The function sets AQ to the minimum value

Mode = 2 and S1 = 1: The function sets AQ to the maximum value

Mode = 3 or a block value is referenced: The function outputs actual analog input value.

Overview