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Chapter 4 - AutomationDirect

1. If you pulse the counter beyond these two maximum counts and Ym 20 reset is OFF the following will happen e Counting UP past 8388607 will cause the count to wrap around and start counting from 8388608 UP i e 8388608 8388607 8388606 etc e Counting DOWN past 8388608 will cause the count to wrap around and start counting from 8388607 DOWN i e 8388607 8388606 8388605 etc If this happens the overflow LED will come ON to let you know this has occurred It would remain ON until power is removed or you manually reset it using by Ym 1 Status Flag for In addition to turning on the OVF LED when there is a counting overflow the HSC will Overflow also mirror the status in Xn 3 This flag will stay ON until Ym 1 is turned ON or power is removed You can use this flag to sound an alarm trigger other events etc Tracking Overflows You may want to track the total number of overflows that occur The program below shows you some example logic that could accomplish this task Assuming that the HSC is in Slot O of the base X3 turns on when there is an overflow X3 INC It will increment whatever is in V3000 1 3000 by 1 everytime X3 goes HIGH Y1 OUT Turn ON Y1 to reset X3 Turn it OFF When Ym 1 goes HIGH the overflow flag will not be set again until an overflow occurs again Summary of Input The chart below summarizes the X and Y output assignments discussed above and Output Rela
2. Select Counting Direction First scan only T 1 Assuming that the HSC is in Slot 0 UP DWN mode Y13 SET amp Cc E 5j oO Q 5 oo Z F ng e Select the UP DWN counting mode Direction of Counting Y14 SET Counts DOWN with INA Counts UP with INB Ym 13 1 Ym 14 1 Setting Up and Controlling the Counting Selecting the Counting Resolution Choose From 3 In the UP DOWN mode the resolution is fixed at 1x However in the quadrature Resolution mode you can control which signal INA or INB and what edges of the signal cause Settings a count change This allows you to effectively double or quadruple the resolution You have three choices e 1x One edge of INA causes count change e 2x Both edges of INA cause count change e 4x All edges of INA and INB cause count change Ym 14 controls the direction of the counting but Ym 16 and Ym 17 in combination control which signal and how many edges will cause the count to change What Causes Count Change Y Function OFF 1x One edge of INA No ON OFF 2x Both edges of INA OFF ON 4x All edges of INA and INB Ym 14 Change state to change count direction Ym 15 ON will invoke home search ON ON 4x All edges of INA and INB Ym 16 ON for x2 count operation
3. Step1 Load the offset value Range 8388608 to 8388607 into V memory Step2 Transfer the value out of V memory by writing it to shared memory Step3 Write the offset value to the current count by either of two ways e Send a signal from a field device attached to the external LD input of the module Ym 22 must be ON to enable this feature This is the external method e Use your ladder logic to turn ON Ym 2 This is the internal method External Method For simplification purposes let s look at an example where you have your HSC in Slot 0 of your base The rung of logic shown below will prepare the HSC to use an offset value Then if you have a field device hooked to the LD terminal connections and you turn the device ON the HSC will will copy the value stored in the shared memory address 04 to 07 offset to the current count In contrast if Ym 22 was OFF the HSC would not respond to any signal at the LD connection In the example below CO will determine if the offset gets written to current count Load offset value of 3500 BCD into V2003 V2004 SPO ON first scan only LDD Step 1 3500 Load value into accumulator Range 8388608 to 8388607 Copy offset value from OUTD V2003 V2004 to shared memory v2003_ CPU memory area SPO i LD Location of HSC in base 1 KO Base 0 and slot 0 Step 2 Note W
4. quadrature mode only Ym 17 must be OFF Ym 17 ON for x4 count operation quadrature mode only Quadrature 1x Operation One Edge INA trigger NA is leading INB so it counts UP INB is leading INA so it counts DOWN See note below INA IN B 1 1 1 1 Tl ME 1 1 1 1 1 1 1 gt Ym 14 OFF q 2 3 4 3 2 1 Ym 14 ON 1 2 3 4 3 2 1 Note In this resolution mode the reason the trailing edge causes a count change when INB leads INA is the change will occur when INB is low only Quadrature 2x Operation Two Edge INA trigger INA is leading INB so it counts UP INB is leading INA so it counts DOWN INA INB 1 1 1 1 1 1 1 TIME 1 1 1 1 1 L 1 1 L 1 1 1 1 1 oS Ym 14 OFF 1 2 3 4 5 6 T 8 7 6 5 4 3 2 1 Ym 14 ON 1 2 3 4 5 6 7 8 7 6 5 4 3 2 1 Quadrature 4x Operation All Edges INA and INB trigger INA is leading INB so it counts UP INB is leading INA so it counts DOWN INA INB A Red Ee E MLA Ld LH ee ee ee ae ee ee ee Saar E E E E ee Ym 14 OFF 1 23 45 67 8 91011 12 13 14 15 1413121110 98 765 4 3 21 Ym 14 ON 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Q Sp Se Ge o oo oS co lt eo Setting Up and Controlling the Counting Why Change the
5. Yii ouT Latch the current count What Is Meant There may be some reason during the course of the program that you want the By Inhibiting the counter to temporarily suspend its counting without resetting or in any way disturbing Count the the current count This is what the inhibiting feature does When this feature is ON inputs from INA and INB are ignored O How Do You Inhibit You have two options here also Op the Count e You can do it externally via a field device attached to the terminals So marked C INH as e You can do it internally by using Ym 10 eS Sample RLL Here is a short segment of ladder logic showing you how to inhibit the count by using for Inhibiting the internal output Ym 10 We have assumed your HSC is in Slot 0 of the base B the Count co Y10 H OUT Inhibit the count Summary of Latch The chart below summarizes the Y output assignments discussed above and Inhibiting Output Relays Y Function No Ym 10 If turned ON the HSC will temporarily inhibit suspend the count Ym 11 If turned ON the HSC will latch the current count into shared memory Rising edge triggered 4 12 Setting Up and Controlling the Counting kej a D ie Controlling the Counting Monitoring Overflow and Resetting Flags What is a Counting As mentioned earlier the HSC counter can count UP to 8388607 maximum or Overflow count DOWN to 8388608
6. a reset on the falling edge Setting Up and Controlling the Counting 411 Latching or Inhibiting the Current Count What Does There may be an application where you want to store the current count after a certain Latching Do amount of time passes or when acertain event has taken place You can capture this information and store it in shared memory without stopping the counting This is called latching It gives you a snap shot of the pulse count for later use in your program How Do You You have two options for triggering the latching process Trigger the e You can do it externally via a field device attached to the terminals Latching Process marked LATCH or e you can do it internally by using Ym 11 In both cases the latching will take place each time there is a transition from OFF to ON If you leave either the field device or Ym 11 in the ON state it will only latch one time at the OFF to ON transition You will have to do a separate transition from OFF to ON every time you make a LATCH requestin order for values to actually be stored Sample RLL Here is a short segment of ladder logic showing you how to latch the count by using for Latching the internal output Ym 11 We have assumed your HSC is in Slot 0 of the base We have used a one shot command here so that CO and Y11 would be ON for only one scan when the CPU sees that X42 is ON co x PD If X42 turns ON CO will turn ON for one scan co
7. the HSC will be configured to count in the UP DOWN mode Select the UP DWN counting mode 09 D F gt a E ko S a 2 oe oO 3 3 Ke 44 Setting Up and Controlling the Counting Selecting the Counting Direction How Ym 13 and Ym 14 Together Determine Counting Direction The status of Ym 14 determines the direction of the counting that is UP or DOWN If you are in the quadrature mode the HSC will determine whether it is to count UP or DOWN by looking at the status of Ym 14 and seeing which of the signals INA or INB is leading The HSC will determine direction of counting by looking at the status of Ym 14 the counting mode Ym 13 and if a quadrature signal whether INA or INB is leading or lagging The table below summarizes how this information is used Mode Status Direction Criteria Used For Determining Direction Ym 13 0 Ym 14 0 Counts UP if INA leads INB Counts DOWN if INB leads INA quadrature Ym 13 0 Ym 14 1 Counts UP if INB lead INA Counts DOWN if INA leads INB quadrature Ym 13 1 Ym 14 0 Counts UP with INA Counts DOWN with INB standard UP DOWN Ym 13 1 Ym 14 1 Counts DOWN with INA Counts UP with INB standard UP DOWN Using this criteria the following sample ladder logic would cause the HSC to count in the UP DOWN mode The count from INA would be DOWN and the count from INB would be UP Ladder Logic to
8. you place a presetin shared memory it tells the HSC This is my target Your target can be any number of pulses in the range 8388608 thru 8388607 Remember negative presets must have an 8 in front of them NOTE If you do not use a preset i e you have no target count always set Ym 20 ON to ensure continuous counting without inadvertent resets Each time your ladder logic instructs the HSC to enable your HSC outputs the HSC will look at three parameters that are stored in shared memory in order to know which output to turn ON Step1 Current count Step2 Preset Step3 Deceleration The HSC then makes a decision on what to do with the outputs CW CCW OUT 1 and OUT2 based on the relationship that it sees On Pages 5 4 and 5 5 we will show you how the relationship between preset and current count determines the status of each output First you load a presetinto shared memory using the same 2 step procedure shown earlier Load preset value into V2004 V2005 SPO ON first scan only LDD Step 1 1 H K6000 Load preset value in accumulator OUTD Copy preset value from v2004 Transfer the value to the CPU memory area V2004 V2005 to shared memory SPO ON first scan only LD Location of HSC in base 1 H K3 Base 0 and slot 3 Step 2 LD KA Transferring 4 bytes preset value LD into shared memory starting at hex 08 Kos meee WT v
9. 2004 from V2004 V2005 NOTE Preset may be loaded at any time but it is not accepted by the HSC until the HSC run bit transitions from off to on There are three X inputs in the I O assignment table that report the status of preset versus the current count You can use the status of each of these in your RLL to trigger events Here is the portion of the table showing you the three X assignments X Function No Xn 0 ON if current count is greater than preset Xn 1 ON if current count is equal to preset Xn 2 ON if current count is less than preset For example the one line of logic below could turn on an alarm when the current count exceeds preset Assume that the HSC is in Slot 0 xo Y43 1 H out Y43 is an audible alarm Setting Up and Controlling the Counting 4 9 Starting and Resetting the Current Count Starting the Assuming you have installed the HSC module in the base properly and connected Counter an encoder to the proper inputs you are ready to start the counting process All that is required is to put the PLC in RUN mode and have the encoder or encoders sending valid signals With this done the HSC will start counting any pulses received at INA or INB It will automatically be storing the accumulated count as the current count in the shared memory Automatically Ym 20 determines when the current count is reset to zero You have two options Resetting the A If
10. Setting Up and Controlling the Counting In This Chapter Introduction to Using DirectSOFT Selecting the Counting Mode Selecting the Counting Direction Specifying an Offset Specifying a Preset Starting and Resetting the Current Count Latching or Inhibiting the Current Count Monitoring Overflow and Resetting Flags 42 Setting Up and Controlling the Counting Introduction to Using DirectSOFT You may recall an earlier example that showed you how to use the CPU RLL program to move the HSC parameters in and out of shared memory The easiest way to create the RLL program is by using our Windows based software DirectSOFT We won t try to show you all of the DirectSOFT features here but it may be helpful for you to understand a few simple concepts You should refer to your DirectSOFT User Manual for a complete overview of the software features Once you enter the Edit mode you will have several ways to enter your program elements Below is a screen showing a portion of the program that has been entered while in the Edit mode We are using the Ladder View Watch Window Ladder View You can use a Watch Window by clicking on the Watch Window icon or by using the Debug New Watch menu option You can also use the hot key CTRL SHIFT F3 to select the same option You can open several Watch Windows if you like Refer to your DirectSOFT documentation for details One example usage for the Wat
11. The answer to Why change the counting resolution is simply a matter of how Counting much control you need for precise positioning You may want to increase the Resolution resolution so that you receive a higher number of counts per encoder shaft revolution This gives you more control Example RLL Assuming that the HSC is in Slot 0 the following logic would select 2x resolution 2x Resolution First scan only quad mode SPO me RST Select the quadrature counting mode Y16 c SET f Select 2x counting resolution Doubles the resolution Y17 _____ RST Example RLL Assuming that the HSC is in Slot 0 the following logic would select 4x resolution 4x Resolution shat apace SPO vas RST Select the quadrature counting mode Y16 SET Select 4x counting resolution Quadruples the resolutiton Y17 ______ SET Default Setting By default Ym 16 0 and Ym 17 0 This means that you are in the 1x resolution mode for quadrature counting until you change the resolution in your ladder logic ae a D 09 Controlling the Counting 4 7 Setting Up and Controlling the Counting Specifying an Offset What is an Offset This is an optional feature but sometimes you may want to start your counting with some number other than zero This is a perfect example of using an offset You can also change the current count on the fly by using an offset Either way itis a three step process
12. Ym 20 OFF the counter will reset to 0 when current count e B If Ym 20 ON the counter will reset to 0 when it reaches the maximum number 8388607 or the minimum number 8388608 Internal Reset You can also use Ym 12 to reset your counter Simply turn it ON in your ladder logic As long as you have Ym 12 ON the current count will remain zero External Reset In order to reset the counter externally you can turn ON the device connected to the Using RST RST terminals of the HSC As long as this signal stays HIGH the current count will remain zero Summary of Reset The chart below summarizes the Y output assignments discussed above Count Relays Y Function No Ym 12 When set to ON HSC resets current count to zero Ym 20 If OFF counter will reset to O when current count preset If ON counter will reset when count is at max or min Q Sp Se Ge o oo oS co eo Setting Up and Controlling the Counting External Reset If you have not invoked Home Search with Ym 15 you can use INZ to reset the Using INZ counter You enable the INZ reset feature by turning Ym 26 ON Since direction of the encoder shaft rotation affects when the Z marker will send the reset pulse the status of Ym 14 change direction output affects which edge of the pulse actually triggers the reset By using INZ to reset the counter you are able to trigger reset at the same shaft position every tim
13. ch Window feature when working with the HSC is to monitor the V memory area where you might be exchanging information back and forth with the HSC s shared memory amp Cc E O vo Q 52 oo Z ng e Setting Up and Controlling the Counting 43 Selecting the Counting Mode Determining Which You need to decide which mode of Quadrature Counting Mode to Use counting to use If you are using a SS quadrature signal input device then Quadrature Encoder obviously you will need to use the cI INA lt 2 quadrature mode If you are using a 2 single channel encoder you will want to use the standard UP DOWN mode The following page shows you the RLL for selecting the counting mode lt a ___INB Leading and lagging signals INZ Pulses once per revolution Quadrature encoders require that you connect to both the INA and INB terminals They can sense direction and are inherently more immune to noise than single encoders Quadrature encoders have a Z marker that will aid in home search applications when connected to INZ by determining a zero or reference point in the angular displacement of the encoder s shaft The single channel encoders used for standard UP DOWN counting do not have Z markers When the HSC is not engaged in home search you can use the Z marker signal at INZ to reset the counte
14. e The table below shows the relationships of the various outputs the count direction the INZ signal and which part of the pulse actually resets the counter Home Count Search INZ Reset Direction Ym 15 Ym 26 Ym 14 Characteristics of the Reset Using INZ OFF ON OFF Resets on rising edge when counting DOWN Resets on falling edge when counting UP OFF ON ON Resets on rising edge when counting UP Resets on falling edge when counting DOWN An Example of INZ Resetting Current Count Under Various Conditions Current Count Value Time gt Rising Edge wm Falling Edge Rising Edge Falling Edge INZ B oy Ym4 26 ___1 Ym 14 kej a D ie On the first pulse of INZ there is no reset because Ym 26 is OFF On the second pulse of INZ there is a reset because Ym 26 is ON Ym 14 is OFF and we re counting UP so the counter resets on the falling edge On the third pulse of INZ there is a reset because Ym 26 is ON Ym 14 is OFF and we are counting DOWN so the counter resets on the leading edge Controlling the Counting On the fourth pulse of INZ there is no reset because Ym 26 is OFF On the fifth pulse of INZ Ym 26 is ON and Ym 14 is ON Because we were counting UP there is a reset on the rising edge a a N eae On the sixth pulse of INZ Ym 26 is ON and Ym 14 is ON Because we were counting DOWN there is
15. e used SPO in LD Transferring 4 bytes offset value he above steps but you K could use any permissive eo contact instead LD into shared memory starting at hex 04 e K04 wT fi V2003 V2004 S D v2003 om o SS Co Step 3 y22 ag 1 H OUT Enable LD input terminals Sc 4 Internal Method If you are using the internal method everything would remain the same except the Ow final rung of logic Step 3 Here you would use CO to turn ON Y2 ea Load offset value of 3500 BCD into V2003 V2004 SPO ON first scan only LDD Ste 1 K Load value into accumulator Ce 3500 Range 8388608 to 8388607 Copy offset value from OUTD V2003 V2004 to shared memory V2003 CPU memory area SPO LD Location of HSC in base KO Base 0 and slot 0 Step 2 Note We used SPO in LD Transferring 4 bytes offset value the above steps but you nm could use any permissive contact instead Er into shared memory starting at hex 04 WT 2003 from V2003 V2004 Co Step 3 y2 1 H OUT Transition Y2 from OFF to ON 48 Setting Up and Controlling the Counting Specifying a Preset amp Cc E 5j oO Q 52 oo Z ng e What is a Preset How Does the Preset Affect the Outputs Loading the Preset Into Shared Memory Checking the Status of a Preset Relative to Current Count Another way of saying preset is to use the word target When
16. r We will show you how to do that in a moment on Page 4 10 With standard counting you can use the UP DOWN Counting two counting input signals INA and Using Two Inputs INB of the D4 HSC One input is used for One Channel Encoders counting UP and the other used for a lt counting DOWN You can t use both eR INA inputs for the same direction of counting f INB q You could be using only one of the inputs if desired In this case the other input UP DOWN Counting terminal should be left unwired You Using One Input control the direction of counting by the aE ESE manner in which you set a certain bit in FU Na a your control program shown later a INB Unused Ladder Logic for You will recall from the I O configuration Determining the table thatthe HSC uses Ym 13 to control Counting Mode the counting mode If you have your HSC as ee in slot 0 this means Y13 is the data point 1 SET you use in your ladder logic By default the mode is set to count as if the signals at INA and INB are from a quadrature encoder Ym 13 OFF If you want standard non quadrature UP DOWN Ym 13 OFF Quadrature counting you have to set Ym 13 to ON Ym 13 ON UP DWN Below is a sample rung of logic that selects the UP DOWN mode For simplicity we have assumed the HSC is in slot 0 When SPO is turned ON first scan only
17. ys for Overflow and XorY Function Flag Reset No Xn 3 If ON it means that you are in overflow If OFF it means you are not in overflow Ym 1 This output relay will reset turn OFF the overflow flag Xn 3 and the OVF LED

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