ALLEN-BRADLEY BULLETIN 1336 IMPACT SCALE FUNCTION BLOCK APPLICATION NOTE # 1336E - 12 August 27, 1997 PURPOSE The purpose of this document is to provide guidelines for wiring and control schemes for the Bulletin 1336 IMPACT AC Drive. This document is to be used as a suggestion only. Users must ensure that installations meet applicable codes and are suitable for the existing conditions. The Bulletin 1336E User Manual should be used as a reference to ensure that proper wire selection, routing and fusing guidelines are followed. Refer to application note #1336E - 4 for an overview of Function Block concepts. WHAT THIS NOTE CONTAINS This note contains descriptions and possible uses for the Scale function block incorporated into the 1336E drive INTENDED AUDIENCE This application note is intended to be used by personnel familiar with the hardware components and programming procedure necessary to operate the Bulletin 1336S. WHERE IT IS USED The diagrams, parameter settings and auxiliary hardware used in this application note are designed to address specific issues in many different applications. Some changes by the User may be necessary to apply the concepts of this document to a specific application. TERMS AND DEFINTIONS [ ] - Indicates a parameter name Link - A link is a software connection between two parameters that lets one parameter receive information from another. - This represents a source which is a link parameter that provides the information. - This represents a destination which is a link parameter receiving the information. DESCRIPTION The Scale function block is used to configure the drive with “function” inputs that perform offset, gain and clamp functions to an input value. To configure the drive with the Scale circuit the [Function Sel] parameter (212) must be programmed appropriately. Refer to figure 1. Faxback Document # 3058 Revision Date 8/27/97 Web location Http://WWW.AB.COM Page 1 of 5 Figure 1 EVALUATING THE FUNCTION INPUTS VALUE 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 The “Function Evaluation Select” parameters (200,203,206) are used to precondition the inputs. The numbers 0-15 correspond to the 16 different evaluations available. Refer to table 1 for the descriptions. Table 1 EVALUATION (1 = on = true = set = closed) (0 = off = false = reset = open) Pass the value directly through the function block Mask the value (logical AND the input value with a value) Send a true value when all bits that are set in the mask are on in the input value Send a true value when all bits that are set in the mask are off in the input value Send a true value when any bits that are set in the mask are on in the input value Send a true value when any bits that are set in the mask are off in the input value Send a true value when the input value is equal to the value of the mask Send a true value when the input value is not equal to the value of the mask Send a true value when the signed input value is < the value of the mask Send a true value when the signed input value is < or = to the value of the mask Send a true value when the signed input value is > the value of the mask Send a true value when the signed input value is > or = to the value of the mask Send a true value when the unsigned input value is < the value of the mask Send a true value when the unsigned input value is < or = to the value of the mask Send a true value when the unsigned input value is > the value of the mask Send a true value when the unsigned input value is > or = to the value of the mask Scale When [Function Sel] is set to thirteen, the Scale function is used to set an input and output range for the value present at In1. The values at In2 and In3 specify the maximum and minimum input values for In1. The output is scaled between the values of In4,In5 (max) and In6,In7 (min). In4 and In6 are Output 1 (whole number), In5 and In7 are Output 2 (fractional number) of the double word output. (In8 is not used) Refer to figure 2. Faxback Document # 3058 Revision Date 8/27/97 Web location Http://WWW.AB.COM Page 2 of 5 Figure 2 In 1 Value +10 +5 0 -5 -10 Output Value 4096 3072 2048 1024 0 APPLICATION CONSIDERATION The Function Input parameters for the multiply/divide block are linkable destination type parameters. This means that other parameter values may be directly sent to, or linked, to these locations. All function inputs that are used by the function block must be programmed with a constant value or have a link. The Function Output parameter is a source parameter. This parameter must be linked to a destination parameter. The LINK menu of the Human Interface Module is used to create parameter links. An example of the link display is shown below. Drive/Inv Status <15> < DESTINATION PARAMETER Use the ▲ or ▼ keys to select the desired Destination Parameter. 0 Arrow Indicates the direction of data Faxback Document # 3058 Revision Date 8/27/97 Web location Http://WWW.AB.COM Page 3 of 5 APPLICATION EXAMPLE Faxback Document # 3058 Revision Date 8/27/97 Web location Http://WWW.AB.COM Page 4 of 5 In the following example the drive is set up to run at a minimum speed of 500rpm and a maximum of 1200rpm. A potentiometer is wired to the analog input and is scaled such that the minimum value that the drive would consider is 500. The maximum value is 3500. This means if the pot is at zero and is increased, the drive would not react until the value for the analog input reached 500. It would then increase speed until the value reached 3500. After that it would not react to the potentiometer. 1.) As soon as the drive is started the speed jumps to 500rpm. 2.) Even though the analog pot is at zero. 3.) As the analog pot increases the speed does not change (dead band). And again at top speed starting to decrease speed there is dead band. Dead band is set up by In2 and In3. 1200RPM (In4) The drive will not go faster than this value. 3 500RPM (In6) The drive will not go slower than this value. 3 1 2 Plot #1 In this example the dead band was removed. Plot #2 Faxback Document # 3058 Revision Date 8/27/97 Web location Http://WWW.AB.COM Page 5 of 5