TABLE OF CONTENTS SECTION TITLE 1.0 INTRODUCTION DESCRIPTION RELATED LITERATURE LADDER LOGIC ELEMENTS...

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4 CG39-26 CONTENTS TABLE OF CONTENTS SECTION TITLE PAGE 1.0 INTRODUCTION DESCRIPTION RELATED LITERATURE LADDER LOGIC ELEMENTS POWER RAILS LINK ELEMENTS HORIZONTAL LINK ELEMENT (H SHUNT) VERTICAL LINK ELEMENT (V SHUNT) CONTACTS NORMALLY OPEN CONTACT (NOC) NORMALLY CLOSED CONTACT (NCC) POSITIVE TRANSITION-SENSING CONTACT (PTC) NEGATIVE TRANSITION-SENSING CONTACT (NTC) COILS COIL SET (LATCH) COIL RESET (UNLATCH) COIL RETENTIVE (MEMORY) COIL SET RETENTIVE (MEMORY) COIL RESET RETENTIVE (MEMORY) COIL POSITIVE TRANSITION-SENSING COIL NEGATIVE TRANSITION-SENSING COIL NEGATED COIL January 1997 i

5 CONTENTS CG39-26 LIST OF FIGURES FIGURE TITLE PAGE 2-1 Example Ladder Logic Network Ladder Logic Power Rails Logic Flow with Vertical Shunts Vertical Shunt NOC and NCC Contact Example PTC and NTC Contact Example Set Coil Example Positive Transition Sensing Coil Example Negative Transition Sensing Coil Example LIST OF TABLES TABLE TITLE PAGE 5-1 State of the Normally Open Contact State of the Normally Closed Contact State of the Positive Transition-Sensing Contact State of the Negative Transition-Sensing Contact State of the Coil State of the Set Coil State of the Reset Coil State of the Retentive Coil State of the Set Retentive Coil State of the Reset Retentive Coil State of the Positive Transition-Sensing Coil State of the Negative Transition-Sensing Coil State of the Negated Coil Moore Products Co. assumes no liability for errors or omissions in this document or for the application and use of information included in this document. The information herein is subject to change without notice. The Moore logo, APACS, the APACS logo,quadlog and 4-mation are trademarks of Moore Products Co. All other trademarks are the property of the respective owners Moore Products Co. All rights reserved. ii January 1997

6 CG39-26 INTRODUCTION 1.0 INTRODUCTION This Guide provides reference information for the Ladder Logic (LL) language of the 4-mation configuration software. It is intended to be used in conjunction with the configuration procedures located in Using the 4-mation Configuration Software (document number CG39-20). This Guide is arranged into the following sections: C Section 1, Introduction C Section 2, Ladder Logic Elements C Section 3, Power Rails C Section 4, Link Elements C Section 5, Contacts C Section 6, Coils 1.1 DESCRIPTION The Ladder Logic (LL) language is one of the four configuration languages of 4-mation. LL simulates hardwired relay logic. Therefore, it lends itself to the configuration of interlock and interface circuits, etc. 1.2 RELATED LITERATURE Document categories can be identified by the prefix (e.g. CGxx-xx) of the document number as listed here: CG = Configuration Guide SD = Service Data SG = Software Guide UM = User's Manual The following 4-mation and other APACS literature is available from Moore Products Co. Generally, all needed documentation is supplied with your system. Refer to it as needed or as directed in text. UM mation Installation and Operation This is a binder which contains the following documents: SG39-12 CG39-20 CG39-21 Getting Started with 4-mation Using the 4-mation Configuration Software 4-mation Software Messages and Diagnostic Codes January

7 INTRODUCTION CG39-26 UM mation Function Block Language This is a binder which contains the following documents: CG39-22 CGQL-3 CG39EVENT-1 CG39FDI-2 CG39FDI-3 APACS Standard Function Blocks QUADLOG Standard Function Blocks Sequence of Event Function Blocks Modbus Master Function Blocks for the APACS ACM Modbus Slave Function Blocks for the APACS ACM UM mation Ladder Logic, SFC & ST Languages This is a binder which contains the following documents: CG39-26 CG39-27 CG39-28 Ladder Logic (this document) Sequential Function Chart Structured Text UM mation, Configuring APACS Hardware This is a binder which contains the following documents: CG39-24 CGQL-4 CG39-25 APACS I/O Module Configuration QUADLOG I/O Module Configuration LIM Configuration UM mation Application Libraries This is a binder which contains the following document: CG39-23 APACS Basic Application Library # 1-2 January 1997

8 CG39-26 LADDER LOGIC ELEMENTS 2.0 LADDER LOGIC ELEMENTS Each element in a ladder logic network should be given a reference. A reference is a variable of Boolean data type that is associated with the element. For example, START is the Boolean variable associated with the normally open contact element shown below. Refer to Using the 4-mation Configuration Software (document number CG39-20) for information on how to enter the reference. LEFT LINK START RIGHT LINK The state of a reference may be different from the state of the ladder logic element. This difference will be explained in the description of each element. All ladder logic elements assume a reference state of FALSE when not assigned a reference. The Ladder Logic language is configured on a 32 x 32 grid of cells called a sheet. In this language, configuration elements are connected together to perform a specific task. The group of connected elements is called a Ladder Logic Network. An example a network is shown in Figure 2-1. The elements permitted in this type of network include: C Ladder Logic Elements (e.g. contacts, coils and shunts) C Standard Function Blocks (SFB) C Derived Function Blocks (DFB) C User Defined Function Blocks (UFDB) C Structured Text (ST) statements (However, no selection or iteration statements are permitted) C Comments C Variables January

9 LADDER LOGIC ELEMENTS CG39-26 Standard Function Block Variable Passed Variable as a reference Local Variable as a reference Coil Contact Shunt Derived Function Block FIGURE 2-1 Example Ladder Logic Network The following sections in this Guide explain each of the ladder logic elements. The ladder logic elements are as follows: C Power Rails C Link Elements Horizontal Link Element (H Shunt) Vertical Link Element (V Shunt) C Contacts Normally Open Contact (NOC) Normally Closed Contact (NCC) Positive Transition-Sensing Contact (PTC) Negative Transition-Sensing Contact (NTC) 2-2 January 1997

10 CG39-26 LADDER LOGIC ELEMENTS C Coils Coil Set (Latch) Coil Reset (Unlatch) Coil Retentive (Memory) Coil Set Retentive (Memory) Coil Reset Retentive (Memory) Coil Positive Transition-Sensing Coil Negative Transition-Sensing Coil Negated Coil As appropriate, refer to documents APACS Standard Function Blocks (document number CG39-22) or QUADLOG Standard Function Blocks (document number CGQL-3) for a description of the standard function blocks that can be used in ladder logic diagrams. # January

11 LADDER LOGIC ELEMENTS CG January 1997

12 CG39-26 POWER RAILS 3.0 POWER RAILS A ladder diagram contains a vertical line on the left side called the left power rail. A ladder diagram also contains a vertical line on the right side called the right power rail. The state of the left power rail is considered to be TRUE. No state is defined for the right power rail. The left power rail on a sheet can be extended by connecting horizontal and vertical shunts (explained below) to the right power rail. See Figure 3-1. Connection of elements to the right power rail can be explicit or implied. For example, the right power rail is implied in Figure 3-1. The position of the right rail defaults to column AF. The rail can be moved closer to the left rail by from the Main Menu Bar by selecting Options, Resize Sheet. FIGURE 3-1 Ladder Logic Power Rails # January

13 POWER RAILS CG January 1997

14 CG39-26 LINK ELEMENTS 4.0 LINK ELEMENTS Link Elements may be either horizontal (Horizontal Shunt) or vertical (Vertical Shunt). Link Elements have an associated state that can be TRUE or FALSE and are used to make connections between contacts, coils, etc. 4.1 HORIZONTAL LINK ELEMENT (H SHUNT) A Horizontal Link Element is displayed as a horizontal line that occupies one cell. H SHUNT A Horizontal Link Element transfers the state of the element in the cell on its left side to the element in the cell on its right side. This ladder element is not the same as the horizontal wiring element of the Function Block language. The Function Block wiring element can transfer analog and Boolean data and does not indicate state on-line, where as the ladder logic horizontal shunt only transfers Boolean data and does indicate state on-line. 4.2 VERTICAL LINK ELEMENT (V SHUNT) A Vertical Link Element is displayed as a vertical line that can connect the elements in two consecutive cells in the same column. V SHUNT The state of the Vertical Link Element is the inclusive OR of the states of the elements on its left side and those connected to it via V Shunts above and below. For example, the state of the Vertical Link Element will be FALSE if the states of all the attached elements to its left are FALSE. The state will be TRUE if the state of any of the attached elements to its left are TRUE. The transfer of state can flow up or down, but only in the direction which enables the rung logic to continue its flow from left to right. For example, Figure 4-1 shows vertical shunts flowing upwards which allows the flow of the rung logic to go from left to right January

15 LINK ELEMENTS CG39-26 FIGURE 4-1 Logic Flow with Vertical Shunts Unlike the Horizontal Shunt, the Vertical Shunt does not always occupy a cell exclusively. If a Vertical Shunt was placed in a cell first, then another object cannot be placed in that cell. However, if another element (contact, horizontal shunt, etc.) existed in a cell, a vertical shunt can be placed there also. Refer the example in Figure 4-2. FIGURE 4-2 Vertical Shunt 4-2 January 1997

16 CG39-26 LINK ELEMENTS Removing a Vertical Link Element requires a special method. Do not use the [Delete] key as this will delete all cell contents, not just the Vertical Link Element. To remove only a Vertical Link Element and preserve the other contents of the cell: 1. On the ladder logic sheet, place the cursor on the cell where the Vertical Link Element is located. 2. Press the Vertical Link Element key [F4] or Select the Vertical Link Element icon with the left mouse button. # January

17 LINK ELEMENTS CG January 1997

18 CG39-26 CONTACTS 5.0 CONTACTS A contact is an element that copies a state to the element on its right side that is equal to the AND of the state of the element on its left side with the given reference. For memory usage and ACM execution time information on all standard configuration elements, see Appendix A in Using the 4-mation Configuration Software (document number CG39-20). 5.1 NORMALLY OPEN CONTACT (NOC) The symbol of a NOC is shown below. The state of the left link is copied to the right link if the state of the associated reference is TRUE. Otherwise, the state of the right link is FALSE. Refer to Table 5-1. TABLE 5-1 State of the Normally Open Contact STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE CONDUCTING NOT CONDUCTING or SATISFIED TRUE SATISFIED X FALSE NOT CONDUCTING Where X indicates any state. 5.2 NORMALLY CLOSED CONTACT (NCC) The symbol of a NCC is shown below. The state of the left link is copied to the right link if the state of the associated reference is FALSE. Otherwise, the state of the right link is FALSE. Refer to Table 5-2. January

19 CONTACTS CG39-26 TABLE 5-2 State of the Normally Closed Contact STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING FALSE CONDUCTING NOT CONDUCTING or SATISFIED FALSE SATISFIED X TRUE NOT CONDUCTING Where X indicates any state. Figure 5-1 contains an example using a Normally Open Contact and a Normally Closed Contact. In the example the following conditions exist: When SWITCH is TRUE and B is TRUE, LIGHT2 is TRUE and CONDUCTING When SWITCH is TRUE and B is FALSE, LIGHT1 is TRUE and CONDUCTING FIGURE 5-1 NOC and NCC Contact Example 5.3 POSITIVE TRANSITION-SENSING CONTACT (PTC) The symbol of a PTC is shown below. The state of the right link is TRUE for one controller scan when a FALSE to TRUE transition of the associated reference is sensed at the same time that the state of the left link is TRUE. The state of the right link is FALSE at all other times. Refer to Table January 1997

20 CG39-26 CONTACTS TABLE 5-3 State of the Positive Transition-Sensing Contact STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING FALSE to TRUE CONDUCTING for Change one scan then NOT CONDUCTING NOT CONDUCTING or SATISFIED FALSE to TRUE SATISFIED Change X FALSE NOT CONDUCTING Where X indicates any state. NOTE Since the PTC conducts for a single scan of the controller and the controller execution speed is greater than the screen update rate, the transitions of the PTC may not be visible while observing a configuration on-line. 5.4 NEGATIVE TRANSITION-SENSING CONTACT (NTC) The symbol of an NTC is shown below. The state of the right link is TRUE for one controller scan when a transition of the associated reference from TRUE to FALSE is sensed at the same time that the state of the left link is TRUE. The state of the right link is FALSE at all other times. Refer to Table 5-4. N TABLE 5-4 State of the Negative Transition-Sensing Contact STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE to FALSE CONDUCTING for Change one scan then NOT CONDUCTING NOT CONDUCTING or SATISFIED TRUE to FALSE SATISFIED Change X TRUE NOT CONDUCTING Where X indicates any state. January

21 CONTACTS CG39-26 NOTE Since the NTC conducts for a single scan of the controller and the controller execution speed is greater than the screen update rate, the transitions of the NTC may not be visible while observing a configuration on-line. Figure 5-2 shows an example of using a Positive Transition-Sensing Contact and a Negative Transition- Sensing Contact. In the example the following conditions exist: C If POS experiences a FALSE to TRUE change when SWITCH is TRUE, then LIGHT1 will CONDUCT for one scan. C If NEG experiences a TRUE to FALSE change when SWITCH is TRUE, then LIGHT2 will CONDUCT for one scan. FIGURE 5-2 PTC and NTC Contact Example # 5-4 January 1997

22 CG39-26 COILS 6.0 COILS A coil copies the state of the link on its left to the link on its right without modification. The coil also stores the state of the left link into an associated Boolean variable (e.g. reference to a Boolean input, output or other Boolean variable). For memory usage and ACM execution time information on all standard configuration elements, see Appendix A in Using the 4-mation Configuration Software (document number CG39-20). 6.1 COIL The symbol of a coil is shown below. The state of the left link is copied to the associated reference and to the right link. Refer to Table 6-1. TABLE 6-1 State of the Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE CONDUCTING NOT CONDUCTING or SATISFIED FALSE NOT CONDUCTING 6.2 SET (LATCH) COIL The symbol of a Set Coil is shown below. The associated reference is in the TRUE state when the left link is in the TRUE state. The reference, but not the coil, remains set to TRUE until reset by another coil. Refer to Table 6-2. ( S) TABLE 6-2 State of the Set Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE CONDUCTING NOT CONDUCTING or SATISFIED Last State NOT CONDUCTING The on-line display of the (S) part of the element is based upon the state of the reference. For example, if the reference is in the TRUE state, then the (S) portion of the element will be displayed in the CONDUCTING state color (i.e. the coil is set). The example in Figure 6-1 demonstrates the functionality of January

23 COILS CG39-26 the Set Coil. When LATCH_ON is TRUE, the LATCH1 set coil, the LIGHT1 coil, the LATCH1 contact, and the LIGHT2 coil are CONDUCTING. If LATCH_ON then turns FALSE, the LATCH1 set coil and the LIGHT1 coil are NOT CONDUCTING, but since the LATCH1 reference remains TRUE, the LATCH1 contact and the LIGHT2 coil remain CONDUCTING. To reset the LATCH1 reference in this example, the reference LATCH_OFF must become TRUE. FIGURE 6-1 Set Coil Example 6.3 RESET (UNLATCH) COIL The symbol of a Reset Coil is shown below. The associated reference is in the FALSE state when the left link is in the TRUE state. The reference, but not the coil, remains reset to FALSE until set by another coil. Refer to Table 6-3. TABLE 6-3 State of the Reset Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING FALSE CONDUCTING NOT CONDUCTING or SATISFIED Last State NOT CONDUCTING The on-line display of the (R) part of the element is based upon the state of the reference. For example, if the reference is in the FALSE state then the (R) portion of the element is displayed in the CONDUCTING state color (i.e. the coil is reset). 6-2 January 1997

24 CG39-26 COILS 6.4 RETENTIVE (MEMORY) COIL The symbol of a Retentive Coil is shown below. The state of the left link is copied to the associated reference variable and to the right link. The retentive feature, which saves the current value through a warm restart, is automatically activated when a reference is assigned to this coil (the RETAIN check box found on the Variable Declaration dialog box is automatically selected). Refer to Table 6-4. ( ) M TABLE 6-4 State of the Retentive Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE CONDUCTING NOT CONDUCTING or SATISFIED FALSE NOT CONDUCTING 6.5 SET RETENTIVE (MEMORY) COIL The symbol of a Set Retentive Coil is shown below. The associated reference is set to TRUE when the left link is in the TRUE state. The reference remains TRUE until reset by another coil (R or RM). The retentive feature, which saves the current value through a warm restart, is automatically activated when a reference is assigned to this coil (the RETAIN check box found on the Variable Declaration dialog box is automatically selected). Refer to Table 6-5. TABLE 6-5 State of the Set Retentive Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING TRUE CONDUCTING NOT CONDUCTING or SATISFIED Last State NOT CONDUCTING January

25 COILS CG RESET RETENTIVE (MEMORY) COIL The symbol of a Reset Retentive Coil is shown above. The associated reference is reset to FALSE when the left link is in the TRUE state. The reference remains reset to FALSE until set by another coil (S or SM). The retentive feature, which saves the current value through a warm restart, is automatically activated when a reference is assigned to this coil (the RETAIN check box found on the Variable Declaration dialog box is automatically selected). Refer to Table 6-6. TABLE 6-6 State of the Reset Retentive Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING FALSE CONDUCTING NOT CONDUCTING or SATISFIED Last State NOT CONDUCTING 6.7 POSITIVE TRANSITION-SENSING COIL The symbol of a Positive Transition-Sensing Coil is shown below. The state of the associated reference is TRUE for one controller scan when a FALSE to TRUE transition of the left link is sensed. The state of the left link is always copied to the right link. Refer to Table 6-7. TABLE 6-7 State of the Positive Transition-Sensing Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT FALSE to TRUE change TRUE for one scan CONDUCTING NOT CONDUCTING or SATISFIED FALSE NOT CONDUCTING CONDUCTING, no change FALSE CONDUCTING The example in Figure 6-2 demonstrates the functionality of the Positive Transition-Sensing Coil. 6-4 January 1997

26 CG39-26 COILS When SWITCH changes from FALSE to TRUE, coil A, coil LIGHT1, contact A and coil LIGHT2 are all CONDUCTING. The very next scan, SWITCH remains CONDUCTING and coil A and coil LIGHT1 remain CONDUCTING. However, contact A and coil LIGHT2 are NOT CONDUCTING because the reference of a Positive Transition-Sensing Coil is TRUE for one scan only. If SWITCH becomes FALSE, then the A and LIGHT1 coils are NOT CONDUCTING. FIGURE 6-2 Positive Transition Sensing Coil Example 6.8 NEGATIVE TRANSITION-SENSING COIL The symbol of a Negative Transition-Sensing Coil is shown below. The state of the associated reference is TRUE for one controller scan when a TRUE to FALSE transition of the left link is sensed. The state of the left link is always copied to the right link. Refer to Table 6-8. TABLE 6-8 State of the Negative Transition-Sensing Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT TRUE to FALSE change TRUE for one scan CONDUCTING NOT CONDUCTING or SATISFIED FALSE NOT CONDUCTING CONDUCTING, no change FALSE CONDUCTING The example in Figure 6-3 demonstrates the functionality of the Negative Transition-Sensing Coil. January

27 COILS CG39-26 When the reference variable SWITCH is TRUE, contact SWITCH, coil B, and coil LIGHT1 are CONDUCTING because the state of the left link is always copied to the right link. Contact B and LIGHT2 are NOT CONDUCTING because the reference of a Negative Transition-Sensing Coil is not TRUE unless a negative transition is sensed. When the reference SWITCH transitions from TRUE to FALSE, the B coil, LIGHT1 coil, and SWITCH contact are NOT CONDUCTING, while the B contact and LIGHT2 coil are CONDUCTING. The very next scan, the SWITCH contact, B coil and LIGHT1 coil remain NOT CONDUCTING while the B contact and LIGHT2 coil change to NOT CONDUCTING because the reference of a Negative Transition-Sensing Coil is TRUE for one scan only. FIGURE 6-3 Negative Transition Sensing Coil Example 6.9 NEGATED COIL The symbol of a Negated Coil is shown below. The inverse of the left link is copied to the associated reference variable. The state of the left link is always copied to the right link. Refer to Table 6-9. TABLE 6-9 State of the Negated Coil STATE OF THE LEFT LINK STATE OF STATE OF REFERENCE ELEMENT CONDUCTING FALSE CONDUCTING NOT CONDUCTING or SATISFIED TRUE NOT CONDUCTING # 6-6 January 1997