Automation Direct D0–DCM User Manual

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D0–DCM Data

Communications

Module

Manual Number D0–DCM–M

WARNING

Thank you for purchasing automation equipment from Automationdirect.com™, doing business as, AutomationDirect. We want your new DirectLOGIC™ automation equipment to operate safely. Anyone who installs or uses this equipment should read this publication (and any other relevant publications) before installing or operating the equipment.

To minimize the risk of potential safety problems, you should follow all applicable local and national codes that regulate the installation and operation of your equipment. These codes vary from area to area and usually change with time. It is your responsibility to determine which codes should be followed, and to verify that the equipment, installation, and operation are in compliance with the latest revision of these codes.

At a minimum, you should follow all applicable sections of the National Fire Code, National Electrical Code, and the codes of the National Electrical Manufacturer’s Association (NEMA). There may be local regulatory or government offices that can also help determine which codes and standards are necessary for safe installation and operation.

Equipment damage or serious injury to personnel can result from the failure to follow all applicable codes and standards. We do not guarantee the products described in this publication are suitable for your particular application, nor do we assume any responsibility for your product design, installation, or operation.

Our products are not fault–tolerant and are not designed, manufactured or intended for use or resale as on–line control equipment in hazardous environments requiring fail–safe performance, such as in the operation of nuclear facilities, aircraft navigation or communication systems, air traffic control, direct life support machines, or weapons systems, in which the failure of the product could lead directly to death, personal injury, or severe physical or environmental damage (”High Risk Activities”). AutomationDirect specifically disclaims any expressed or implied warranty of fitness for High Risk Activities.

For additional warranty and safety information, see the Terms and Conditions section of our Desk Reference. If you have any questions concerning the installation or operation of this equipment, or if you need additional information, please call us at 770–844–4200.

This publication is based on information that was available at the time it was printed. At AutomationDirect we constantly strive to improve our products and services, so we reserve the right to make changes to the products and/or publications at any time without notice and without any obligation. This publication may also discuss features that may not be available in certain revisions of the product.

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AVERTISSEMENT

Nous vous remercions d’avoir acheté l’équipement d’automatisation de Automationdirect.comE, en faisant des affaires comme, AutomationDirect. Nous tenons à ce que votre nouvel équipement d’automatisation DirectLOGIC™ fonctionne en toute sécurité. Toute personne qui installe ou utilise cet équipement doit lire la présente publication (et toutes les autres publications pertinentes) avant de l’installer ou de l’utiliser.

Afin de réduire au minimum le risque d’éventuels problèmes de sécurité, vous devez respecter tous les codes locaux et nationaux applicables régissant l’installation et le fonctionnement de votre équipement. Ces codes diffèrent d’une région à l’autre et, habituellement, évoluent au fil du temps. Il vous incombe de déterminer les codes à respecter et de vous assurer que l’équipement, l’installation et le fonctionnement sont conformes aux exigences de la version la plus récente de ces codes.

Vous devez, à tout le moins, respecter toutes les sections applicables du Code national de prévention des incendies, du Code national de l’électricité et des codes de la National Electrical Manufacturer’s Association (NEMA). Des organismes de réglementation ou des services gouvernementaux locaux peuvent également vous aider à déterminer les codes ainsi que les normes à respecter pour assurer une installation et un fonctionnement sûrs.

L’omission de respecter la totalité des codes et des normes applicables peut entraîner des dommages à l’équipement ou causer de graves blessures au personnel. Nous ne garantissons pas que les produits décrits dans cette publication conviennent à votre application particulière et nous n’assumons aucune responsabilité à l’égard de la conception, de l’installation ou du fonctionnement de votre produit.

Nos produits ne sont pas insensibles aux défaillances et ne sont ni conçus ni fabriqués pour l’utilisation ou la revente en tant qu’équipement de commande en ligne dans des environnements dangereux nécessitant une sécurité absolue, par exemple, l’exploitation d’installations nucléaires, les systèmes de navigation aérienne ou de communication, le contrôle de la circulation aérienne, les équipements de survie ou les systèmes d’armes, pour lesquels la défaillance du produit peut provoquer la mort, des blessures corporelles ou de graves dommages matériels ou environnementaux (”activités à risque élevé”). La société AutomationDirect nie toute garantie expresse ou implicite d’aptitude à l’emploi en ce qui a trait aux activités à risque élevé.

Pour des renseignements additionnels touchant la garantie et la sécurité, veuillez consulter la section Modalités et conditions de notre documentation. Si vous avez des questions au sujet de l’installation ou du fonctionnement de cet équipement, ou encore si vous avez besoin de renseignements supplémentaires, n’hésitez pas à nous téléphoner au 770–844–4200.

Cette publication s’appuie sur l’information qui était disponible au moment de l’impression. À la société AutomationDirect, nous nous efforçons constamment d’améliorer nos produits et services. C’est pourquoi nous nous réservons le droit d’apporter des modifications aux produits ou aux publications en tout temps, sans préavis ni quelque obligation que ce soit. La présente publication peut aussi porter sur des caractéristiques susceptibles de ne pas être offertes dans certaines versions révisées du produit.

Marques de commerce

La présente publication peut contenir des références à des produits fabriqués ou offerts par d’autres entreprises. Les désignations des produits et des entreprises peuvent être des marques de commerce et appartiennent exclusivement à leurs propriétaires respectifs. AutomationDirectE nie tout intérêt dans les autres marques et désignations.

Nulle partie de ce manuel ne doit être copiée, reproduite ou transmise de quelque façon que ce soit sans le consentement préalable écrit de la société Automationdirect.comE Incorporated. AutomationDirect conserve les droits exclusifs à l’égard de tous les renseignements contenus dans le présent document.

Manual Revisions

If you contact us in reference to this manual, please remember to include the revision number.

Title: DL05/06 Data Communications Module Manual Number: D0–DCM–M

Issue Date Description of Changes

Original 8/05 Original Issue

Table of Contents

Chapter 1: Introduction

Manual Overview 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Purpose of this Manual 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Supplemental Manuals 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Who Should Read this Manual 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Technical Support 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Conventions Used 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Key Topics for Each Chapter 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Hardware Features 1–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Applications 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

As a DirectNET Interface 1–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

As an Extra Communication Port 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

As a MODBUS RTU

Chapter 2: Installation, Network Cabling and Module Specifications

Inserting the D0–DCM into the PLC 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Module Installation 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Building the Communication Cable 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consideration 1: Physical Configuration 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consideration 2: Electrical Specification RS232 or RS422/485 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . .

Consideration 3: Cable Schematics 2–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consideration 4: Cable Specifications 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Consideration 5: Installation Guidelines 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Wiring Diagrams 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Port 1 RS–232 Network 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Port 2 RS–232 Network 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Port 2 RS–485 Network 2–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D0–DCM Port 2 RS–422 Network 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Module Specifications 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Specifications 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 1 Specifications 2–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Specifications 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Status Indicators 2–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network Interface 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 3: D0–DCM Module Configuration Registers

DCM Port Configuration Registers 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Module Configuration Registers 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Comm Port Default Configuration Parameters 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A: Port 1 – Transmit Mode, Protocol 3–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B: Port 1 – Station Address, Baud Rate, Parity 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

C: Port 2 – RTS On/Off delay, Transmit Mode, Protocol, Comm Time–out, RS–485 Mode 3–6. . . .

D: Port 2 – Station Address, Baud Rate, Data Bit, Stop Bit, Parity 3–8. . . . . . . . . . . . . . . . . . . . . . . .

E: Port 2 – Character Time–out 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

F: Port 1 and 2 Setup and Completion Code 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

G: Port 1 and 2 Reset Time–out 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents

DL05 Port Setup Examples 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 1 Example: Slave Mode Only 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example: Slave Mode 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example: DirectNet Master 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example: MODBUS RTU Master 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DL06 Port Setup Examples 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 1 Example: Slave Mode Only 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example:Slave Mode 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example: DirectNet Master 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Port 2 Example: MODBUS RTU Master 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 4: RLL Programming for Communications

PLC-to-PLC Communications 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

How RLL is Used for Communications 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network Instructions 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Read (RX) and Write (WX) Instructions 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Building the Read (RX) or Write (WX) Routine 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Second LD Instruction 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The LDA Instruction 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Read (RX) Instruction 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Write (WX) Instruction 4–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Addressing the Different Memory Types 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bit Memory 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Word Memory and Aliases 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DL05 CPU 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DirectSOFT32 is Flexible 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DL06 CPU 4–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Special Relays for Communications 4–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program with One Read Instruction 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Master PLC 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Slave PLC 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Master PLC 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Slave PLC 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example Program with One Write Instruction 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Master PLC 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Slave PLC 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Master PLC 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Program for the Slave PLC 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Integrating Multiple Read and Write Instructions 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Interlocking Relays 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First RX/WX Instruction 4–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Second RX/WX Instruction 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Third RX/WX Instruction 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Returning to the First RX/WX Instruction 4–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Shift Register 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Store If Equal 4–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First RX/WX Instruction 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Second RX/WX Instruction 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Third RX/WX Instruction 4–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents

Chapter 5: D0–DCM Using MODBUSr RTU

Network Slave Operation 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MODBUS Function Codes Supported 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Determining the MODBUS Address 5–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

If Your Host Software or Master Requires the Data Type and Address 5–3. . . . . . . . . . . . . . . . . . . . .

Example 1: V2100 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 2: Y20 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 3: T10 Current Value 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 4: C54 5–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

If the Host Software or Master Requires an Address ONLY 5–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 1: V2100 5–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 2: Y20 5–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 3: C54 5–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Network Master Operation 5–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

MODBUS Function Codes Supported 5–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PLC Memory Supported for Master Operation 5–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 1: Calculating Word PLC Address 5–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Example 2: Calculating Discrete Input PLC Address 5–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Building the Read (RX) or Write (WX) Routine 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 1: Identify DCM Slot Location and Slave 5–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 2: Load Number of Bytes to Transfer 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 3: Specify Master Memory Area 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 4: Specify Slave Memory Area 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Communications from a Ladder Program 5–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Multiple Read and Write Interlocks 5–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

Introduction

In This Chapter. . . .

— Manual Overview — D0–DCM Hardware Features — D0–DCM Applications

1–2

Introduction

Manual Overview

The Purpose of this Manual

Introduction

Supplemental Manuals

This manual is designed to allow you to setup and install your DL05/06 Data Communications Module (D0–DCM). This is the only manual you will need if you are using the D0–DCM as an extra general purpose communication port for your DL05/06 PLC system. If you plan on using the D0–DCM as a network master or slave for a DirectNET/MODBUS RTU network, this manual covers the basic steps for setting up the D0–DCM and the RX/WX instructions needed in your RLL program.

If you plan on using a PC as the network master, it may be helpful to read the DirectNET manual first. In either case, the DirectNET manual can be useful because it provides detailed descriptions of network configurations, various cable connections, etc.

Depending on which products you have purchased, there may be other manuals that are necessary or helpful for your application. These are some suggested manuals:

User Manuals

• DirectNET Network Guide part number DA–DNET–M

• DirectSoft32 Programming Software part number PC–DSOFT32–M

Who Should Read this Manual

Installation and

Safety Guidelines

Technical Support

If you plan to use your D0–DCM to communicate with another PLC, you will need the appropriate user manual for the other PLC.

If you plan to use your D0–DCM module as an interface to HMI or PC Control software or to an Operator Interface panel, you will need to refer to the documentation for that product.

If you need an additional communications port for your DL05/06 PLC and you understand the basics of installing and programming PLCs, this is the right manual for you. This manual gives you the information you need to set up an active port on the D0–DCM module.

We strive to make our manuals the best in the industry and rely on your feedback in reaching our goal. If you cannot find the solution to your particular application, or, if for any reason you need additional technical assistance, please call us at

770–844–4200.

Our technical support team is glad to work with you in answering your questions. They are available weekdays from 9:00 a.m. to 6:00 p.m. Eastern Time. We also encourage you to visit our website where you can find technical and nontechnical information about our products and our company.

www.automationdirect.com

DL05/06 Data Communications Module, 1st Edition, 08/05

Conventions Used

1–3

Introduction

Key Topics for Each Chapter

The “light bulb” icon in the left-hand margin indicates a tip or shortcut.

The “note pad” icon in the left–hand margin indicates a special note.

The “exclamation mark” icon in the left-hand margin indicates a warning or caution. These are very important because the information may help you prevent serious personal injury or equipment damage.

The beginning of each chapter will list the key topics that can be found in that chapter.

Introduction Installation and

DL05/06 Data Communications Module, 1st Edition, 08/05

Safety Guidelines

1–4

D0–DCM Hardware Features

Introduction

The following diagram shows the D0–DCM hardware components. The communication parameters are configured using DirectSOFT32. There are no DIP switches to set on this module.

The D0–DCM requires ladder logic programming to configure its communication parameters, unless the default settings are acceptable for the application. If the D0–DCM is to be used as a network master, you must use ladder logic code to configure this parameter.

D0–DCM

Port 1: RS–232 Communication Port

Status Indicators (shown below)

Installation and

Safety Guidelines

Port 2:

RS232/422/485

Communication Port

Status Indicators

TX1: Port 1 Transmitting Data (Green)

RX1: Port 1 Receiving Data (Green); Error (Red)

TX1

RX1 ERR

DATA COMM

PORT2

TX2

RX2

ERR

TX2: Port 2 Transmitting data (Green)

RX2: Port 2 Receiving Data (Green); Error (Red)

The D0–DCM Data Communications Module is a general purpose communications interface that c an b e u sed i n a D L05/06 P LC s ystem. T he m odule c an g o in any o ption slot. This module is primarily used for several reasons:

• As an extra general purpose communications port to connect to a personal computer or operator interface

• As a network master or slave interface to a DirectNET network (port 2); port 1 functions as a DirectNET slave only

• As a network master or slave interface to a MODBUS port 1 functions as a MODBUS

RTU slave only

RTU network (port 2);

• As a K–sequence slave (both ports)

DL05/06 Data Communications Module, 1st Edition, 08/05

Applications

As a DirectNET Interface

1–5

Introduction

Introduction Installation and

The D0–DCM can be used as a network interface for applications that require data to be shared between PLCs, or between PLCs and an intelligent device (such as a host computer). The D0–DCM can be configured as either a master or slave station and allows you to upload or download virtually any type of system data including Timer/Counter data, I/O information, and V-memory information.

DirectNET Master

Issues requests to slave

stations

PC or D0–DCM

master can

communicate with

DirectNET Slaves

Using a D0–DCM as a network Master

The D0–DCM can be used with a DL05 or DL06 CPU to serve as a network master . A master is the network station that initiates requests for data from other stations on the network). You simply use special RLL instructions (RX and W X) inside o f your R LL program to initiate the data exchange. The D0–DCM takes communication requests issued by the PLC program i nstructions and automatically converts these requests into network commands that read data from or write data to another network station.

DirectNET Slaves

Slaves respond to the master’s request

Possible Slaves

S DL05/DL06 CPU (either port) S DL05/DL06 CPU w/D0–DCM S D2–240/250–1/260 CPU (either

port)

S D2–240/250–1/260 w/ D2–DCM S D3–330/330P w/ DCU S D3–340/350 (either port) S D4–430/440 (bottom port) S D4–450 (phone jack or bottom port) S Any DL405 CPU w/ D4–DCM

Safety Guidelines

Using a D0–DCM as a network Slave

The D0–DCM can also be used with a DL05 or DL06 CPU to serve as a network slave station. In this case, the D0–DCM “listens” to the network for any messages that contain the D0–DCM’s address. The D0–DCM deciphers the network commands, carries out the request to read or write data, and sends confirmation and/or information to the master station.

DL05/06 Data Communications Module, 1st Edition, 08/05

Possible Masters

S DL05/06 CPU (port 2) S DL05/06 CPU w/ D0–DCM S 250–1/260 CPU (bottom port)

S D2–240/250–1/260 CPU

w/ D2–DCM

S D3–340/350 CPU (bottom

port)

S Any DL405 CPU w/ D4–DCM S D4–450 CPU (bottom port) S Host computer w/KEPDirect

for PLCs

1–6

Introduction

As an Extra Communication Port

Introduction

As a MODBUSRTU Network Interface

The D0–DCM ports are similiar to the ports on the DL05 and DL06 CPUs. In general, if you can connect a device to the CPU ports, then you can also connect the same device to the D0–DCM. These devices can be a variety of things, such as operator interfaces or personal computers.

Quickly add extra

communication ports*

* Number of option modules is limited by the DL06 available power budget.

The D0–DCM can be used as a master or slave interface to connect your DL05/06 system to a M ODBUS RTU network. P ort 1 c an o nly s erve a s a MODBUS R TU s lave. Port 2 can serve a s a M ODBUS R TU master o r slave. This m anual does not describe the MODBUS protocol. We recommend that you reference the Gould MODBUS Protocol Reference Guide (P1-MBUS-300 Rev. B) for details on the protocol. There may be more recent editions of this manual, so check with your MODBUS supplier before ordering the documentation.

Installation and

Safety Guidelines

DL05/06 Data Communications Module, 1st Edition, 08/05

For information about the MODBUS protocol see the Group Schneider Web site at: www.schneiderautomation.com. At the main menu, select Support/Services, Modbus, Modbus Technical Manuals, PI–MBUS–300 Modbus Protocol Reference Guide or search for PIMBUS300.

MODBUS® Master

MODBUS Network using RTU Protocol

Network

Slave

DL06 Slave with

D0–DCM

As a slave station....

responding to network reĆ quests

Network

Slave

Installation, Network Cabling and Module Specifications

In This Chapter. . . .

— Inserting the D0–DCM into the PLC — Building the Communication Cable — Wiring Diagrams — Module Specifications

2–2

Installation and Setup

Inserting the D0–DCM into the PLC

D0–DCM Module Installation

and Setup

Installation

Remove the front protective option slot cover by squeezing the pinch tabs and lifting the cover off. Remove the top option slot cover using small flat–head screwdriver or similiar device. Be sure PLC power is off when installing the D0–DCM module.

DL05 Front View

Pinch Tabs to remove front slot cover

C0 C2 Y16Y14Y13Y11Y6Y4Y3Y1

C1 C3Y0 Y15Y12Y10 Y17Y7Y5Y2

2.0AOUTPUT: 6–240V

N.C.

40VA50–60HzPWR: 100–240V

D0–06DR

PWR RUN CPU TX1 RX1 TX2 RX2

LGG

)

AC(N)24V

AC(L

50 – 60Hz2.0A,6 – 27V

0 1 2 3 4 5 6 7 10 11 12 13 14 15 16 17 20 21 22 23

INPUT: 12 – 24V3 – 15mA

DL06 Front View

C0 C4C2X1 X3 X4 X6 X11X13X14 X16 X21 X23N.C.

C1 C3X2 X5 X7 X10 X12 X15X17 X20 X22X0 N.C.

PORT1 RUN STOP

PORT2

TERM

Remove top slot cover with small flat–head screwdriver

Installation and

Safety Guidelines

DL06 Top View

Insert the module into the open slot in the DL05 or into any one of the four slots in the DL06. Locate the module so the printed information is oriented in the same direction as the markings on the PLC. Be careful to align the female connector on the printed circuit board of the module with the male connector on the PLC mother board. Press the module into the slot until the front of the module is flush with the front of the PLC. Check the DL06 power budget to be sure that it remains within the power supply limits before installing more modules.

NOTE: The DL05 CPU’s communication feature for the D0–DCM requires DirectSOFT32 Version 3.0c (or later) and firmware version 5.00 (or later). The DL06 requires DirectSOFT32 version V4.0, build 16 (or later) and firmware version 1.90 (or later). See our website for more information: www.automationdirect.com.

DL05/06 Data Communications Module, 1st Edition, 08/05

Installation and Setup

Building the Communication Cable

There are several considerations that help determine the type of cable needed for your D0–DCM application. The next few pages discuss these considerations in detail.

Consideration 1: Physical Configuration

The D0–DCM can be used in either a point-to-point or multi-drop configuration. A point-to-point connection only has two stations, a master and a slave. Use the point-to-point configuration to connect a personal computer, an operator interface, or an intelligent device to a single D0–DCM. You must also use this configuration when you want to connect a DirectNET master station to a single DirectNET slave station. Use the multi-drop configuration to connect one master to two or more slaves (90 slave maximum).

Point to Point – RS–232C

PC or OI

Master

2–3

Installation

and Setup

D0–DCM Slave

DL06 Master

Multi-drop – RS–422/485

DirectNET or

MODBUS

RTU

Masters

DL05 Slave

DirectNET Slaves

Safety Guidelines

Installation and

D0–DCM

Data Communications Module, 1st Edition, 08/05

2–4

Installation and Setup

Consideration 2: Electrical Specification RS232C or RS422/485

Consideration 3: Cable Schematics

and Setup

Installation

Port 1

6 5

4 3 2 1

The D0–DCM can support RS–232 (ports 1 and 2) or RS–422/485 (port 2) communication. Your application and configuration choice will help determine which electrical specification is best for you. If you are using multi-drop, you must use RS–422 or RS–485. If you are using point-to-point, you may have a choice between RS–232C and RS–422/485. You can use RS–232 if the cable length is less than 50 feet and if the cable will not be subjected to induced electrical noise that is commonly found near welders, large motors, or other devices that create large magnetic fields. You must use RS–422/485 for all other applications. RS–422/485 allows longer cable distances (up to 3300 feet) and provides higher noise immunity.

Although the network configuration and electrical specification are important, the type of devices being connected to the D0–DCM are just as important. The exact cable schematic needed really depends on a combination of all three things. The following diagram shows the port pinouts for the D0–DCM.

D0–DCM Pinouts

Port 2

Port 1 Pin Descriptions

10V 25V 3 RXD Receive Data (RS–232) 4 TXD Transmit Data (RS–232) 5 RTS Request to Send 60V

Installation and

Safety Guidelines

RJ12 Phone Jack

Connector

15-pin Female HD Connector

Port 2 Pin Descriptions

1 5V 5 VDC 2 TXD2 Transmit Data (RS–232) 3 RXD2 Receive Data (RS–232) 4 RTS2 Ready to Send (RS–232C 5 CTS2 Clear to Send (RS–232) 6 RXD2– Receive Data – (RS–422/485) 7 0V Logic Ground 8 0V Logic Ground 9 TXD2+ Transmit Data + (RS–422/485)

10 TXD2 – Transmit Data – (RS–422/485)

11 RTS2 + Request to Send + (RS–422/485) 12 RTS2 – Request to Send – (RS–422/485 13 RXD2 + Receive Data + (RS–422/485) 14 CTS2 + Clear to Send + (RS422/485) 15 CTS2 – Clear to Send – (RS–422/485)

DL05/06 Data Communications Module, 1st Edition, 08/05

Installation and Setup

2–5

Consideration 4: Cable Specifications

Consideration 5: Installation Guidelines

Although many types of cables may work for your application, we recommend you use a cable that is constructed to offer a high degree of noise immunity . The following specifications are to be used as a guideline.

Structure Shielded, twisted-pair. . . . . . . . . . . . . . . . . . . . . . .

(RS232 only uses two wires and a ground)

Conductor size 24 AWG or larger. . . . . . . . . . . . . . . . . .

Insulation Polyethylene. . . . . . . . . . . . . . . . . . . . . . .

Shield Copper braid or aluminum foil. . . . . . . . . . . . . . . . . . . . . . . . . .

Impedance 100W @ 1MHz. . . . . . . . . . . . . . . . . . . . . .

Capacitance 60pf / meter or less. . . . . . . . . . . . . . . . . . . .

Y our company may have guidelines for cable installation. If so, you must check those before you begin the installation. Here are some general things to consider.

• Don’t run cable next to larger motors, high current switches, or transformers. This may cause noise problems.

• Route the cable through an approved cable housing to minimize the risk of accidental cable damage. Check local and national codes to choose the correct method for your application.

• Consider redundant cabling if the application data is critical. This allows you to quickly reconnect all stations while the primary cable is being repaired.

Installation

and Setup

Cable Shield Grounding — It is important to ground the cable shield to minimize the possibility of noise. The preferred method is to connect one end of the cable shield to the connector housing. If noise problems are still present and you have a good earth ground for the cabinet, you must connect one end of the shield to the cabinet earth ground. Don’t ground both ends of the shield because this will create induced noise on the cable.

Step 1: Strip back about 2.5” of the shield.

2.5”

Step 2: Crimp a ring connector onto the shield.

Step 3: Secure the shield to the connector shell.

Safety Guidelines

Installation and

Data Communications Module, 1st Edition, 08/05

2–6

Installation and Setup

Wiring Diagrams

D0–DCM Port 1 RS–232 Network

Modular Connector

and Setup

Installation

123456

6-pin Female

TXD

RXD

D0–DCM Port 2 RS–485 Network

TXD+ / RXD+

TXD 4 RXD 3

0V 1

Termination Resistor

D0–DCM PORT 1

D0–DCM Port 2 RS–232 Network

TXD+ / RXD+

OR Loop Back

CTS

RTS

RXD

TXD

Signal GND

RTS

CTS

TXD RXD

GND

TXD+ / RXD+

CTS–

CTS+

Installation and

Safety Guidelines

RTS–

RTS+

RXD+

TXD+

TXD– / RXD–

Signal GND

Connect shield

TXD–

RXD–

to signal ground

Cable: Use Belden 9841 or equivalent

CTS–

CTS+

RTS–

RTS+

TXD– / RXD–

TXD+

RXD+

TXD–

RXD–

TXD– / RXD–

Signal GND

DL05/06 Data Communications Module, 1st Edition, 08/05

D0–DCM Port 2 RS–422 Network

Installation and Setup

RXD+ RXD– TXD+ TXD– Signal GND

PC/PLC Master

Cable: Use Belden 9729 or equivalent

9 TXD+ 10 TXD– 13 RXD+ 6 RXD– 11 RTS+

12 RTS– 14 CTS+

15 CTS– 70V

Termination Resistor on last slave only

PORT 2

(D0–DCM)

RS–422 Slave

RS–422/485 Multi-drop Termination Resistors — It is important you add

termination resistors at each end of the RS422/485 line. This helps reduce data errors during data transmission. You must select resistors that match the cable impedance. For example, a typical 22 AWG solid conductor cable with 4.5 twists per foot has a typical impedance of about 120 ohm. There are two ways to actually connect the resistors.

• Line-to-Line — this method balances the receive data lines (IN+ and IN–) and requires one resistor at each end of the line. (The cable diagrams we’ve provided show this method, but you can use either).

• Line-to-Ground — this method also balances the receive data lines, but common mode noise rejection is improved significantly. This method requires two resistors at each end of the line. Also, since there are two resistors, the sum total of both resistors must match the cable impedance.

2–7

Installation

and Setup

Data Communications Module, 1st Edition, 08/05

Safety Guidelines

Installation and

2–8

Module Specifications

General Specifications

and Setup

Installation

Installation and Setup

Power Budget Requirement 250mA @ 5 VDC

(not including external 5VDC consumption)

Maximum Number of Modules DL05: 1; DL06: 4 Operating Temperature 32° F to 131° F (0° to 55° C) Storage Temperature –4° F to 158° F (–20° to 80° C) Operating Humidity 5 to 95% (non-condensing) Air Composition No corrosive gases permitted Vibration MIL STD 810C, Method 514.2 Shock MIL STD 810C, Method 516.2 Voltage Isolation 1000 VAC, 1 minute duration Insulation Resistance 10M ohms at 500 VDC

Port 1 Specifications

Installation and

Safety Guidelines

Noise Immunity NEMA ICS3–304, UL, CE, (FCC Class A)

Class 1, Division 2 (C1D2)

Weight 1.75 oz. (50g)

Connector 6–pin female modular (RJ12) Communications RS–232

Protocol

(auto–dectection)

DirectNET slave K-sequence slave MODBUS® RTU slave

Station Number 0 – 247 Communication Data 8 data bits, 1 start bit, 1 stop bit (fixed) Parity Bit None, Odd

Baud Rates 9600, 19200, 38400, 57600, 115200 bps

Transmit Mode ASCII, Hex

Maximum Distance RS–232: 50ft (15 meters)

Port 1

6 5

4 3 2 1

Port 1 Pin Descriptions

10V 25V 3 RXD Receive Data (RS–232) 4 TXD Transmit Data (RS–232) 5 RTS Request to Send 60V

DL05/06 Data Communications Module, 1st Edition, 08/05

Port 2 Specifications

Installation and Setup

Connector

15–pin female high–density D–shell

Communications RS–232

RS–422/485

Protocol

(auto–dectection)

DirectNET master/slave K-Sequence slave MODBUS® RTU master/slave Non–sequence (ASCII IN/OUT)

Station Number 0 – 247 Communication Data 8/7 data bits, 1 start bit, 1/2 stop bits Parity Bit None, Odd, Even

Baud Rates 300, 600, 1200, 4800, 9600, 19200, 38400,

57600, 115200 bps Transmit Mode ASCII, Hex Communications Time–out Base time x (1–50)

2–9

Installation

and Setup

Status Indicators

Response Delay Time 0/2/5/10/20/50/100/500ms Character Time–out 0–9999ms

Maximum Distance RS232 – 15 m

RS422/485 – 1000m

Port 2

Port 2 Pin Descriptions

1 5V 5 VDC 2 TXD2 Transmit Data (RS–232) 3 RXD2 Receive Data (RS–232) 4 RTS2 Ready to Send (RS–232) 5 CTS2 Clear to Send (RS–232) 6 RXD2– Receive Data – (RS–422/485) 7 0V Logic Ground 8 0V Logic Ground

9 TXD2+ Transmit Data + (RS–422/485) 10 TXD2 – Transmit Data – (RS–422/485) 11 RTS2 + Request to Send + (RS–422/485) 12 RTS2 – Request to Send – (RS–422/485 13 RXD2 + Receive Data + (RS–422/485) 14 CTS2 + Clear to Send + (RS422/485) 15 CTS2 – Clear to Send – (RS–422/485)

Indicator State Definition

TX1 (Green) ON Port 1 transmitting data

Safety Guidelines

Installation and

RX1 (Green) ERR (Red)

ON ON

Port 1 receiving data Port 1 Timeout, NAK or Exception

Response TX2 (Green) ON Port 2 transmitting data RX2 (Green)

ERR (Red)

ON ON

Port 2 receiving data

Port 2 Timeout, NAK or Exception

Response

Data Communications Module, 1st Edition, 08/05

D0–DCM Module Configuration Registers

In This Chapter. . . .

— DCM Port Configuration Registers — DL05 Ladder Logic Port Setup Examples — DL06 Ladder Logic Port Setup Examples

3–2

D0–DCM Setup

DCM Port Configuration Registers

Module Configuration Registers

DCM Port

Configuration

The table below lists the special V-memory locations used by the DL05 and DL06 PLCs for the D0–DCM module. The following pages define each registers function.

Module Configuration

Parameters

Port 1–Transmit Mode

(ASCII/Hex), Protocol

Port 1–Station Address,

Baud Rate , Parity Port 2–RTS On/Off Delay,

Transmit Mode (ASCII/

Hex), Protocol, Comm Time–out, RS–485 Mode Select

Port 2–Station Address,

Baud Rate, Data Bit , Stop Bit , Parity

Port 2–Character Time–

out

Port1/Port 2 – Setup

Completion Code

Port 1/Port 2–

Reset Time–out

Word

Offset

+0000 V7700 V700 V710 V720 V730

+0001 V7701 V701 V711 V721 V731

+0002 V7702 V702 V712 V722 V732

+0003 V7703 V703 V713 V723 V733

+0006 V7706 V706 V716 V726 V736

+0007 V7707 V707 V717 V727 V737

DL05 and DL06 Option Slot

DL05

V7730 V7730 V7731 V7732 V7733

DL06 Slot 1

DL06

Slot 2

DL06

Slot 3

DL06

Slot 4

Comm Port Default Configuration Parameters

Installation and

Safety Guidelines

On power up, the DCM will write the necessary data to the V–memory configuration registers to result with the following default port communications parameters. If you need to change any of the default settings, you must use ladder logic code to update the appropriate configuration register.

Default Settings

Parameter Port 1 Port 2 Baud Rate 9600bps 19200bps Parity Odd Protocol K–Sequence/DirectNet/MODBUS

(auto–detect) Station Address 1 Data Bits 8 (fixed) 8 Stop Bits 1 (fixed) 1

DL05/06 Data Communications Module, 1st Edition, 08/05

3–3

D0–DCM Setup

Protocol Selection:

Communications Port for DirectSOFT32 Programming: If you plan to program the CPU through the D0–DCM, then you can use either DirectNET protocol or our proprietary K-sequence protocol.

Computer or Operator Interface: If you’re using the D0–DCM to connect a computer or operator interface, check your documentation to see which protocol the PC or OI is using.

MODBUS® RTU: The D0–DCM can serve as a MODBUS® slave (port1 and 2) or as a MODBUSmaster (port 2 only).

Communication Timeout:

developing your own DirectNET programs. By disabling the timeout, you can send one DirectNET component without any communication timeout problems. If you have this

timeout disabled and a communication error does occur, you must restart communications by sending a retry or an End of Transmission (EOT) command. If you want to know more, see the DirectNET manual for details.

Transmit Mode:

fastest communication possible, use HEX mode, which is the default. The difference is in the way the data is represented. The same data is twice as long in ASCII format, so if there’s more data, it takes longer to transfer. If you have a device on the network that requires ASCII mode, then configure the DCM for ASCII mode, otherwise, use HEX mode.

Baud Rate:

115.2Kbps. All stations must have the same baud rate before the communications will operate correctly. Usually, you should use the highest baud rate possible unless noise

problems appear. If noise problems appear, try reducing the baud rates.

Parity: RTS Delay Times:

waits to send the data after it has raised the RTS signal line. This is normally set to 0, and is typically only adjusted if you are using the D0–DCM with a radio modem. If you are using the D0–DCM with a radio modem, check your modem documentation to help you choose the proper setting. Also, if you’re considering the use of a modem, check out Appendix D. It may be of some help. RTS Off Delay – the delay time specifies the amount of time the D0–DCM will wait to reset the RTS line after sending the data.

Address Selection

have a unique address. If you’re using the D0–DCM as a master, make sure you select address 0. For example, a RLL communications program, the DirectSOFT32 Programming Software, and our KEPDirect for PLCs all use the decimal equivalent of the HEX address. It’s easy to convert from hex to decimal.

Choose between none, even and odd parity for error checking.

Select between ASCII and HEX modes of data representation. If you want the

There are several baud rate selections available ranging from 300bps to

On Delay – The delay time specifies the amount of time the D0–DCM

: The addresses do not have to be consecutive, but each station must

Communication Timeout Disable is normally used only if you’re

Configuration

DCM Port

Safety Guidelines

Installation and

DL05/06 Data Communications Module, 1st Edition, 08/05

3–4

D0–DCM Setup

A: Port 1 – Transmit Mode, Protocol

DCM Port

Configuration

Use word +0000 to set Port 1:

• K–Sequence slave, DirectNET slave or MODBUS RTU slave protocol (or auto–detect for all three protocols)

• HEX or ASCII transmit mode

word +0000

1 5

MSB LSB

Protocol

Transmit Mode

Set all unused bits to zero.

Port 1: Transmit Mode

Mode Bit 3 HEX Mode 0 ASCII Mode 1

Port 1: Protocol

Protocol Bit 7–4

(Hex) K–Sequence 8 1 0 0 0 DirectNet 4 0 1 0 0 MODBUS RTU 2 0 0 1 0 K–Seq / D–Net

/MODBUS RTU

E 1 1 1 0

Bit 7 Bit 6 Bit 5 Bit 4

07654321

Installation and

Safety Guidelines

DL05/06 Data Communications Module, 1st Edition, 08/05

D0–DCM Setup

3–5

B: Port 1 – Station Address, Baud Rate, Parity

Use word +0001 to set Port 1:

• Station address ranges from 0–247 (00–F7 Hex)

• Baud rates ranging from 9.6K to 115.2K bps

• Odd or No parity

word +0001

1514131

MSB

Parity

Set all unused bits to zero.

Address Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 00 0 0 0 0 0 0 0 0 01 0 0 0 0 0 0 0 1 02 0 0 0 0 0 0 1 0 – – – – – F6 1 1 1 1 0 1 1 0 F7 1 1 1 1 0 1 1 1

111

987654321

Baud Rate

Station Address

LSB

Port 1: Station Address

Configuration

DCM Port

Port 1: Baud Rate

Baud Rate Bit 10 Bit 9 Bit 8

9.6 K bps 0 0 0

19.K bps 0 0 1

38.4K bps 0 1 0

57.6K bps 0 1 1

115.2K bps 1 0 0

Port 1: Parity

Parity Bit 14 No Parity 0 Odd Parity 1

DL05/06 Data Communications Module, 1st Edition, 08/05

Safety Guidelines

Installation and

3–6

D0–DCM Setup

C: Port 2 – RTS On/Off delay, Transmit Mode, Protocol, Comm Time–out, RS–485 Mode

Use word +0002 to set Port 2:

• K–Sequence slave, DirectNET slave or MODBUS RTU slave protocol (or auto–detect for all three protocols)

• HEX or ASCII transmit mode

• RTS On and Off delay times

• Communication Time–out

• Echo Suppression

word +0002

1514131

MSB

RTS on delay

111

Echo Suppression

987654321

Comm Time–out

Protocol

Transmit Mode

LSB

RTS off delay

Set all unused bits to zero.

DCM Port

Configuration

Installation and

Safety Guidelines

Port 2: RTS Off Delay

Time (ms) Bit 2 Bit 1 Bit 0 0 0 0 0 2 0 0 1 5 0 1 0 10 0 1 1 20 1 0 0 50 1 0 1 100 1 1 0 500 1 1 1

Base Time–out for K–Seq/D–Net = 800ms Base Time–out for MODBUS = 500ms

Port 2: Transmit Mode

Mode Bit 3 HEX Mode 0 ASCII Mode 1

DL05/06 Data Communications Module, 1st Edition, 08/05

Port 2: Protocol

Protocol Bit 7–4

(Hex) K–Sequence 8 1 0 0 0 DirectNet 4 0 1 0 0 MODBUS RTU 2 0 0 1 0 Non–Sequence 1 0 0 0 1 K–Seq / D–Net

/MODBUS RTU

K–Seq, D–Net, MODBUS RTU

Base Time x 1 0 0 0 0 Base Time x 1.2 2 0 0 1 Base Time x 1.5 5 0 1 0

Base Time x 2 10 0 1 1

Base Time x 5 20 1 0 0

Base Time x 10 50 1 0 1 Base Time x 20 100 1 1 0

Base Time x 50 500 1 1 1

E 1 1 1 0

Port 2: Communication Time–out (ms)

Bit 7 Bit 6 Bit 5 Bit 4

Non–Sequence

Protocol

Bit 10 Bit 9 Bit 8

3–7

D0–DCM Setup

Configuration

DCM Port

Port 2: Echo Suppression

Mode Bit 11 RS–422/485: 4–wire

RS–232 RS–485: 2–wire 1

Port 2: RTS On Delay

Time (ms) Bit 14 Bit 13 Bit 12 0 0 0 0 2 0 0 1 5 0 1 0 10 0 1 1 20 1 0 0 50 1 0 1 100 1 1 0 500 1 1 1

Safety Guidelines

Installation and

DL05/06 Data Communications Module, 1st Edition, 08/05

3–8

D0–DCM Setup

D: Port 2 – Station Address, Baud Rate, Data Bit, Stop Bit, Parity

DCM Port

Configuration

Use word +0003 to set Port 2:

• Station address ranges from 0–247 (00–F7 Hex)

• Baud rates ranging from 9.6K to 115.2K bps

• Data Bit Length (7 or 8 bits)

• Stop Bit Length (1 or 2 bits)

• Odd, Even or No Parity

word +0003

1514131

MSB

Parity

Stop Bit

Address Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 00 0 0 0 0 0 0 0 0 01 0 0 0 0 0 0 0 1 02 0 0 0 0 0 0 1 0 ––––– F6 1 1 1 1 0 1 1 0 F7 1 1 1 1 0 1 1 1

111

Data Bit

987654321

Baud Rate

Station Address

Set all unused bits to zero.

LSB

Port 2: Station Address

Installation and

Safety Guidelines

DL05/06 Data Communications Module, 1st Edition, 08/05

Port 2: Baud Rate

Baud Rate Bit 11 Bit 10 Bit 9 Bit 8 300 bps 0 0 0 0 600 bps 0 0 0 1 1200 bps 0 0 1 0 2400 bps 0 0 1 1 4800 bps 0 1 0 0 9600 bps 0 1 0 1

19.K bps 0 1 1 0

38.4K bps 0 1 1 1

57.6K bps 1 0 0 0

115.2K bps 1 0 0 1

Port 2: Data Bit

Length Bit 12 8 Bit 0 7 Bit 1

Port 2: Stop Bit

Length Bit 13 1 Bit 0 2 Bit 1

Port 2: Parity

Parity Bit 15 Bit 14 No Parity 0 0 Odd Parity 0 1 Even Parity 1 0

3–9

D0–DCM Setup

Configuration

DCM Port

E: Port 2 – Character Time–out

Use word +0006 to set Port 2:

• Character Time–out (BCD)

This parameter is used when the DCM is used as a MODBUS RTU master.

word +0006

1514131

MSB

Bit 15–0 time 0 3.5 characters 1–9999 (BCD) time–out (ms)

111

Port 2: Character Time–out

987654321

Character Time–out (BCD)

LSB

Safety Guidelines

Installation and

DL05/06 Data Communications Module, 1st Edition, 08/05

3–10

Port 1: Bit 0 7

D0–DCM Setup

F: Port 1 and 2 Setup and Completion Code

G: Port 1 and 2 Reset Time–out

Word +0007 is used for Port 1 and Port 2 to :

• request that the DCM recognizes changes in the port(s) communication parameters from default or previous settings

• confirm that Port 1 and Port 2 configuration is complete

word +0007

1 5

MSB

Set all unused bits to zero.

Loading a K0055 (BCD) into word +0007 will request that the DCM recognizes (looks for) new or desired port communication parameters that are written to the DCM port configuration registers. If the requested changes are valid, a 00AA (hex) will then be written to word +0007. If the desired or new communications are invalid or out of range, an error code 00E* (Hex) will be written to word +0007. The last digits indicate the address that has an error. For example, error code 00E2 means that word +0002 has an error.

Use word +0024 to set Port 1 and Port 2:

• Reset Time–out in seconds

Port Configuration Completion Code

07654321

LSB

DCM Port

Configuration

Installation and

Safety Guidelines

The communication port will reset after the specified time after the port goes from the BUSY state to the IDLE state.

word +0024

1514131

MSB

Port 1: Bit 0–7 Port 2: Bit 15–8

111

Port 2 Reset Time–out (BCD)

Port Time(s) Function

987654321

Port 1 Reset Time–out (BCD)

Reset Time–out

0 Disable 1–99 Enable

LSB

DL05/06 Data Communications Module, 1st Edition, 08/05

DL05 Port Setup Examples

3–11

D0–DCM Setup

Port 1 Example: (This port can serve as slave only)

Port 2 Example: Slave Mode

SP0

LD KE0

OUT V7700

LD K4001

OUT V7701

LD K55

OUT V7707

LD KE0

Selects auto–detect protocol mode (K–seq, D–Net and MODBUS) and HEX transmit mode.

Write configuration data into V7700.

Selects station address 1, baud rate of 9600bps and odd parity.

Write configuration data into V7701.

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V7707.

Selects auto–detect protocol mode (K–seq, D–Net and MODBUS), HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232

Configuration

DCM Port

OUT V7702

Write configuration data into V7702.

Selects station address 1, baud rate

LD K4601

OUT V7703

of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V7703.

K55 is the port setup completion

LD K55

code that must be used to request that the CPU recognizes the new/desired port parameters

OUT V7707

Write configuration data into V7707.

DL05/06 Data Communications Module, 1st Edition, 08/05

Safety Guidelines

Installation and

3–12

D0–DCM Setup

Port 2 Example: DirectNet Master

Port 2 Example: MODBUS RTU Master

DCM Port

Configuration

SP0

LD K40

OUT V7702

LD K4601

OUT V7703

LD K55

OUT V7707

LD K20

Selects DirectNet protocol, HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232

Write configuration data into V7702.

Selects station address 1, baud rate of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V7703.

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V7707.

Selects MODBUS protocol, HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232

Installation and

Safety Guidelines

OUT V7702

LD K4601

OUT V7703

LD K0

OUT V7706

LD K55

OUT V7707

Write configuration data into V7702.

Selects station address 1, baud rate of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V7703.

Selects 3.5 characters length time–out.

Write configuration data into V7706.

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V7707.

DL05/06 Data Communications Module, 1st Edition, 08/05

DL06 Port Setup Examples

The following examples assumes the D0–DCM is installed in slot 1.

3–13

D0–DCM Setup

Port 1 Example: Slave Mode Only

Port 2 Example: Slave Mode

SP0

LD KE0

OUT V700

LD K4001

OUT V701

LD K55

OUT V707

LD KE0

OUT V702

Selects auto–detect protocol mode (K–seq, D–Net and MODBUS) and HEX transmit mode.

Write configuration data into V700 (based on module slot location).

Selects station address 1, baud rate of 9600bps and odd parity.

Write configuration data into V701 (based on module slot location).

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V707 (based on module slot location).

Selects auto–detect protocol mode (K–seq, D–Net and MODBUS), HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232

Write configuration data into V702 (based on module slot location).

Configuration

DCM Port

Safety Guidelines

Installation and

Selects station address 1, baud rate

LD K4601

OUT V703

of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V703 (based on module slot location).

K55 is the port setup completion

LD K55

code that must be used to request that the CPU recognizes the new/desired port parameters

OUT V707

Write configuration data into V707 (based on module slot location).

DL05/06 Data Communications Module, 1st Edition, 08/05

3–14

D0–DCM Setup

Port 2 Example: DirectNet Master

Port 2 Example: MODBUS RTU Master

DCM Port

Configuration

SP0

LD K40

OUT V702

LD K4601

OUT V703

LD K55

OUT V707

LD K20

OUT V702

Selects DirectNet protocol, HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232

Write configuration data into V702 (based on module slot location).

Selects station address 1, baud rate of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V703 (based on module slot location).

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V707 (based on module slot location).

Selects MODBUS protocol, HEX transmit mode, RTS On/Off delay times are set to zero and RS–422/485 (4–wire) / RS–232C

Write configuration data into V702 (based on module slot location).

Installation and

Safety Guidelines

DL05/06 Data Communications Module, 1st Edition, 08/05

LD K4601

OUT V703

LD K0

OUT V706

LD K55

OUT V707

Selects station address 1, baud rate of 19200bps, odd parity, 8–bit data length and 1 stop bit.

Write configuration data into V703 (based on module slot location).

Selects 3.5 characters length time–out.

Write configuration data into V706 (based on module slot location).

K55 is the port setup completion code that must be used to request that the CPU recognizes the new/desired port parameters

Write configuration data into V707 (based on module slot location).

RLL Programming for Communications

In This Chapter. . . .

— PLC-to-PLC Communications — How RLL is Used for Communications — Network Instructions

— Addressing the Different Memory Types — Special Relays for Communications — Example Program with One Read Instruction — Example Program with One Write Instruction — Integrating Multiple Read and Write Instructions

4–2

PLC-to-PLC Communications

Getting Started

How RLL is Used for Communications

RLL Programming for Communications

This chapter steps you through the development of a Relay Ladder Logic (RLL) program to enable one PLC to communicate with another PLC. For the experienced programmer of DirectLOGIC PLCs, the communication programs presented in this chapter will be simple to follow . If you have never programmed a DirectLOGIC PLC, you may want to refer to the DirectSOFT32 Programming Software User Manual and the User Manual for your PLC for additional information.

NOTE: The programs described in this chapter are not used for communication between a PC and a PLC. For PC-to-PLC communications, please see the product documentation for the PC software you are using.

DirectSOFT32 Programming Software provides Read and Write instructions (RX/WX) for PLC-to-PLC communication over a network. The Read and Write instructions are part of the ladder logic program running in the CPU of the initiating, or master, PLC. These instructions tell the initiating CPU to send a message over the serial network to a responding, or slave, PLC. The initiating PLC’s Read or Write communication finds its destination by the slave address of the responding PLC.

Guidelines

User Application

RLL Programming

for Communications

Master DCM

O U

CPU CPU

T P U

Slave 1

O U

Slave 2

T P

U T

Slave 3

CPUCPU

NOTE: When all slave’s addresses are set to 0 (zero), the master D0–DCM can write data to all slaves at the same time using the WX instruction. This is referred to as “broadcast mode”. If this mode is used, the master DCM cannot use the RX instruction to read data from individual slaves.

O U

T P

U T

C O M

T P

U T

DL05/06 Data Communications Module, 1st Edition, 08/05

Network Instructions

4–3

RLL Programming for Communications

Read (RX) and Write (WX) Instructions

Building the Read (RX) or Write (WX) Routine

The Read (RX) and Write (WX) instructions are used by the master PLC to Read a block of data from another PLC or Write a block of data to another PLC. To perform their functions, the RX and WX boxes must be preceded in the ladder logic program by two Load instructions and one Load Address instruction.

The Load and Load Address instructions load communication parameters into the accumulator and the first and second level of the accumulator stack. The RX or WX instruction takes these parameters from the stack and the accumulator and prepares the data to be sent over the network. If you need to know more about the function of the accumulator and the accumulator stack, refer to the User Manual for your PLC.

For network communications, you build the Read (RX) or Write (WX) instructions into a routine which requires the four instructions you see to the right. The function of each of these instructions is explained below or on the next page. They

A aaa

must be used in the sequence shown.

LDA

O aaa

RX or WX

A aaa

User Application

Guidelines

The First LD Instruction

The first Load (LD) instruction accepts either a constant or a variable. Use a “K” to designate the number as a constant. Use a “V” if you are entering the address of a register. The contents of that register perform the same function as the constant shown below . For example, you could use V2000 in place of K0114. If the contents of V2000 is the number “114,” the function would be the same. Using a variable allows changing parameters while the program is running. It is recommended, however, t o use a constant when possible.

DCM Slot Number

Master PLC

Upper Byte

1140

Lower Byte

SlaveMaster DCM

Slave Address # (Hex)

Slave Device on Network

K114

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

4–4

RLL Programming for Communications

The Second LD Instruction

Getting Started

The LDA Instruction

Guidelines

User Application

RLL Programming

for Communications

The second Load (LD) instruction determines the length of the data block to be transmitted during the Read or Write communication. This instruction will also accept two data types. Use a “K” to designate the number as a constant. Use a “V” if you are entering the address of a register.

For Word Memory data, you must use a multiple of two bytes between 2 and 128. For Bit Memory data, you can use any multiple of one byte between 1 and 128. For more information about addressing Word and Bit Memory, see page 4-6.

PLC Memory

The Load Address (LDA) instruction specifies the V-memory address of the beginning memory register in the master PLC. The data block to be transmitted will begin at this address and extend the number of bytes specified in the preceding LD instruction. The leading “O” indicates this is an octal number. Simply substitute the letter “O” for the “V” in the V-memory designation. For example, V40600 becomes O40600.

Read instructions copy the data block from the slave PLC memory into the master PLC memory.

Write instructions copy the data block from the master PLC memory into the slave PLC memory.

K114

4 words = 8 bytes

K114

LDA

O40600

Master PLC

DL05/06 Data Communications Module, 1st Edition, 08/05

V40577 V40600 V40601 V40602 V40603

V40604

RLL Programming for Communications

s e

4–5

Read (RX) Instruction

The Read (RX) instruction specifies the memory location to be read from the slave PLC.

A block of data is read that begins at the specified memory location and extends the number of bytes specified in the second LD instruction.

In this example, the eight byte block of data beginning at C100 and ending at C177 in the slave PLC is read (copied) into the master PLC’s memory beginning at V40600.

Master PLC

V40577 V40600 V40601 V40602 V40603

V40604

byte

word 4 words = 8 bytes

byte

Slave PLC

bit

LDA

C100C177

bit

K114

O40600

C100

V40603 V40604 V40605 V40606 V40607

V40610

User Application

Guidelines

Write (WX) Instruction

The Write (WX) instruction specifies the memory location to be written to in the slave PLC.

A block of data is written that begins at the specified memory location and extends the number of bytes specified in the second LD instruction.

In the example, the 8-byte block of data beginning at V40600 and ending at V40603 in the master PLC is written (copied) into the

lave PLC’s memory beginning at C100 and

nding at C177.

Master PLC

byte

V40577 V40600 V40601 V40602 V40603

V40604

byte

Slave PLC

bit

C100C177

LDA

bit

K114

O40600

C100

V40603 V40604 V40605 V40606 V40607

V40610

for Communications

RLL Programming

word

4 words = 8 bytes

DL05/06 Data Communications Module, 1st Edition, 08/05

4–6

Addressing the Different Memory Types

Getting Started

Bit Memory

Word Memory and Aliases

RLL Programming for Communications

Some data types are inherently 16 bits long, for example timer and counter current values. Other data types are 1 bit long, for example: discrete inputs and outputs. Word-length and bit-length data are mapped into Word Memory, also known as V-memory, which allows you to address any of the different memory types as 16-bit words.

Bit memory can be addressed in Read and Write instructions by the name of the first bit of any byte. If your second LD instruction contains the constant K8, eight bytes will be transmitted. If you use C0 in your RX or WX instruction, you will transmit the eight bytes from C0 through C77.

In the example below, V40600 is the V-memory designation for the sixteen bits from C0 through C17. Aliases are a convenient substitute for V-memory designations, and can be used interchangeably in Read and Write instructions. VC0 is the alias for V40600. Either nomenclature addresses the same 16 bits.

The alias is simply the name of the first bit in a group of sixteen bits, with V added as a prefix. For example, VC0 represents the 16 bits beginning with C0. Word Memory, Bit Memory and Aliases all use the octal numbering system.

Word Memory Address V40600

Guidelines

User Application

RLL Programming

for Communications

= VC0 (Alias)

V40601 = VC20

V40602 = VC40

V40603 = VC60

C1C2C3C4C5C6C7C10C11C12C13C14C15C16C17 C0

C37 C36 C35 C34 C33 C32 C31 C30 C27 C26 C25 C24 C23 C22 C21 C20

C57 C56 C55 C54 C53 C52 C51 C50 C47 C46 C45 C44 C43 C42 C41 C40

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

The following Write routines are all equivalent. DirectSOFT32 gives you the flexibility to identify the responding PLC’s memory area in three different ways, as shown below.

K114

LDA

O40600

C100

DL05/06 Data Communications Module, 1st Edition, 08/05

LDA

O40600

VC100

LDA

O40600

V40605

RLL Programming for Communications

4–7

DirectSOFT32 is Flexible

DL05 CPU

DL06 CPU

You can address the different data types by any available convention shown in the tables that follow . The largest block of data that can be sent in a single Read or W rite operation is 128 bytes. The smallest block of data is one byte for Bit Memory types and two bytes, or one word for Word Memory types. The octal numbering system is used for all addresses in these tables.

DL05 CPU

Data Types Bit Memory Word Memory Alias

Timer Current Values None V0 – V177 TA0 – TA177 Counter Current Values None V1000 – V1177 CTA0 – CTA177 User Data Words None V1200 – V7377 None Input Points X0 – X377 V40400 – V40417 VX0 – VX360 Output Points Y0 – Y377 V40500 – V40517 VY0 – VY360 Control Relays C0 – C777 V40600 – V40677 VC0 – VC760 Special Relays SP0 – SP777 V41200 – V41237 VSP0 – VSP760 Timer Status Bits T0 – T177 V41100 – V41107 VT0 – VT160 Counter Status Bits CT0 – CT177 V41140 – V41147 VCT0 – VCT160 Stages S0 – S377 V41000 – V41017 VS0 – VS360

DL06 CPU

Data Types Bit Memory Word Memory Alias

User Application

Guidelines

Timer Current Values None V0 – V377 TA0 – TA177 Counter Current Values None V1000 – V1177 CTA0 – CTA177 User Data Words None V400 – V677

V1200 – V7377

V10000 – V17777 Input Points X0 – X777 V40400 – V40437 VX0 – VX760 Output Points Y0 – Y777 V40500 – V40537 VY0 – VY760 Control Relays C0 – C1777 V40600 – V40677 VC0 – VC1760 Special Relays SP0 – SP777 V41200 – V41237 VSP0 – VSP760 Timer Status Bits T0 – T377 V41100 – V41117 VT0 – VT160 Counter Status Bits CT0 – CT177 V41140 – V41147 VCT0 – VCT160 Stages S0 – S1777 V41000 – V41077 VS0 – VS1760 Remote I/O GX0 – GX3777

GY0 – GY3777

V40000 – V40177

V40200 – V40377

None

VGX0 – VGX3760 VGY0 – VGY3760

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

4–8

Special Relays for Communications

Getting Started

RLL Programming for Communications

The DirectLOGIC PLCs provide internal contacts (bits) for monitoring the status of communications. The internal contacts are called Special Relays (there are other Special Relays used for other purposes). There are two Special Relays for each slot in the PLC that will be used by DCM module. The two relays perform the following functions:

S Communication Busy – This bit is on when the communication module

is busy transmitting or receiving. You must use this bit, or relay contact, to prevent overwriting your Read or Write (RX/WX) instructions.

S Communication Error – This bit is on when an error occurred in the

last RX or WX communication. This error automatically clears (the bit resets to zero) when another RX or WX instruction executes.

Guidelines

User Application

RLL Programming

for Communications

For example, Special Relays SP124 and SP125 correspond to an DCM module in slot 3 of the DL06 PLC.

The Special Relay SP125 is used in the example to energize the output Y50, indicating a communication error has occurred. This Special Relay must appear earlier in the program than your RX or WX instruction because it is turned off (reset to zero) when a subsequent Read or Write instruction is executed.

The Special Relay SP124 indicates the DCM is busy. When SP124 is on, the normally closed contact opens to prevent executing another RX or WX instruction until the last one is completed. The appropriate busy bit must be used as a NC contact on every RX/WX instruction rung in the program.

DL05 Special Relays

Relay Option Slot Communication busy SP120

Communication error SP121

SP124

Y50SP125 SET

K304

LDA

DL06 Special Relays

Relay Slot 1 Slot 2 Slot 3 Slot 4 Communication busy SP120 SP122 SP124 SP126

Communication error SP121 SP123 SP125 SP127

DL05/06 Data Communications Module, 1st Edition, 08/05

RLL Programming for Communications

Program with One Read Instruction

The Ladder View screen below is the program development screen in DirectSOFT32 Programming Software. This four rung program is explained in detail on page 4–10. This is a complete program although its function is very limited. There is also a two rung program that runs in the slave PLC, and it is also explained on page 4–10. This example assumes the DCM is in slot 2 of a DL06 PLC.

Program for the Master PLC

4–9

Program for the Slave PLC

When the input (X0) to the slave PLC is turned on (transitions from 0 to 1), the C0 bit in the master PLC also transitions from 0 to 1. The program in the master PLC causes Y0 to turn on in response to the C0 bit.

For example DL05/06 communications programs, go to www.automationdirect.com

technical support website > Example programs> Coummunications

EP–COM–005.

Master example: This project contains simple logic for reading the inputs from a DL05/06 slave and placing their status in C0–C17 in the master . It also writes C17–C37 to the outputs on the slave. Slave example: This project can be used in conjunction with the master project to setup the slave to turn off its outputs if the master PLC stops communicating with it.

> example #

User Application

Guidelines

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

4–10

RLL Programming for Communications

Program for the Master PLC: Rung 1

Getting Started

Rung 2

Rung 3

Guidelines

User Application

In our example, the normally open contact labeled C0 is an internal control relay. When C0 is on, discrete output Y0 is energized.

The second rung uses a Special Relay to identify a communication error. In the example, SP123 is on if a communication error is present for slot two. Use different Special Relays if your DCM module is in a different slot (see page 4-8). We use SP123 to turn on an indicator light connected to a discrete output.

The Special Relay labeled SP122 is on when slot 2 is busy transmitting or receiving. The Read instruction may take longer than one PLC scan to complete. Use this Special Relay to prevent overwriting the previous Read instruction with each PLC scan.

2140

Lower Byte

Slave PLCMaster PLC

Slave # (Hex)

Upper Byte

DCM Slot #

SP123

SP122

OUT

SET

LD K214

LD K2

LDA O40600

Number of bytes to be transferred. Max = 128 bytes.

Beginning address in the in master PLC, expressed as an octal number.

RLL Programming

for Communications

Rung 4

Beginning address in the slave PLC.

All DirectLOGIC PLCs use an END statement to identify the final rung of the main body of the program.

Program for the Slave PLC

This two-rung program resides in the slave PLC’s CPU. Its function is simply to use the X0 contact to turn on the internal control relay, C100.

DL05/06 Data Communications Module, 1st Edition, 08/05

RX VC100

END

C100

OUT

END

RLL Programming for Communications

Example Program with One Write Instruction

The Ladder View screen below is the program development screen in DirectSOFT32 Programming Software. This four-rung program is explained in detail on page 4–12. This is a complete program although its function is very limited. There is also a two-rung program that runs in the responding PLC. It is also explained on page 4–12.This example assumes the DCM is in slot 2 of a DL06 PLC.

Program for the Master PLC

4–11

Program for the Slave PLC

When the input (X0) to the master PLC is turned on (transitions from 0 to 1), the C100 bit in the slave PLC also transitions from 0 to 1. The program in the slave PLC causes Y0 to turn on in response to the C100 bit.

NOTE: The slave PLC logic is a basic example only. If the master/slave communication fails, the bits written to the slaves from the master will remain in the same state last written from the the master.

For example DL05/06 communications programs, go to www.automationdirect.com

technical support website > Example programs> Coummunications

EP–COM–005.

> example #

User Application

Guidelines

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

4–12

RLL Programming for Communications

Program for the Master PLC: Rung 1

Getting Started

Rung 2

Rung 3

Guidelines

User Application

In our example, the normally open contact labeled X0 is a toggle switch input to a discrete input module. When X0 is on, Control Relay C0 is energized.

The second rung uses a Special Relay to identify a communication error. In the example, SP123 is on if there is a communication error present in slot 2. Use different Special Relays if your DCM module is in a d i fferent slot (see page 4-8). We use SP123 to turn on an indicator light connected to a discrete output.

The Special Relay labeled SP122 is on when slot 2 is busy transmitting or receiving. The Write instruction may take longer than one PLC scan to complete. Use this Special Relay to prevent overwriting the previous Write instruction with each PLC scan.

Master PLC

DCM Slot #

Upper Byte

2140

Lower Byte

Slave PLC

Slave # (Hex)

SP123

SP122

OUT

SET

LD K214

LD K2

LDA O40600

Number of bytes to be transferred. Max = 128 bytes.

Beginning address in the in master PLC, expressed as an octal number.

RLL Programming

for Communications

Rung 4

Beginning address in the slave PLC.

All DirectLOGIC PLCs use an END statement to identify the final rung of the main body of the program.

Program for the Slave PLC

This two-rung program resides in the slave PLC’s CPU. Its function is simply to take the C100 contact and convert it to a real output, Y0.

DL05/06 Data Communications Module, 1st Edition, 08/05

C100

WX VC100

END

OUT

END

RLL Programming for Communications

Integrating Multiple Read and Write Instructions

Multiple Read and Write instructions require interlocks for sequencing because only one RX/WX instruction can be processed at once. Using interlocks, one RX/WX instruction is processed in each scan until all RX/WX instructions have been executed. After the last instruction, the sequence then begins again at the first RX/WX instruction.

Without interlocks, the RX/WX instructions would be executed in an unpredictable order, and some might be executed many times before others are executed once. The interlocks serve to open (disconnect) the ladder circuits for all Read and Write instructions except the one that should be processed on the current CPU scan.

We show two methods of creating the interlocks necessary for sequencing multiple Read and Write instructions:

S Sequenced Internal Control Relays S Shift Register

We will step you through the development of the interlocks using both methods. The two examples shown perform the same function. Only the interlocks are different.

4–13

Interlocking Relays

NOTE: To fully understand the material in this section, you will first need to

understand the Example Programs on pages 4–9 and 4–1 1, as well as the material in the Network Instructions section, beginning on page 4–3.

The following program segment sequences through three RX/WX instructions (two Write instructions and one Read instruction). You can develop your own program incorporating either of the two interlocking control strategies and expanding the number of interlocks to accommodate the number of RX/WX instructions in your program.

It is easy to see the function of the interlocking relays if we construct a truth table first. Across the top of the truth table we

show internal control relays that we are considering using for our sequencing strategy. We have used C50 through C52 for our chart, but any contacts that are not used for other purposes in your program will work just as well.

Down the left side of the chart, we list the number of RX/WX instructions we may want to use in our RLL program.

The three contacts in this truth table will accommodate as many as eight Read or Write instructions. Our program only has three RX/WX instructions so we only need to use two contacts (see why on page 4-14). We will use C50 and C51. One additional contact (C53) would give us 32 combinations since the number of combinations expands as the power of 2.

Truth Table C52 C51 C50 First RX/WX 0 0 0 Second RX/WX 0 0 1 Third RX/WX 0 1 0 Fourth RX/WX 0 1 1 Fifth RX/WX 1 0 0 Sixth RX/WX 1 0 1 Seventh RX/WX 1 1 0 Eighth RX/WX 1 1 1

User Application

Guidelines

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

4–14

Getting Started

RLL Programming for Communications

Our three RX/WX instructions can be sequenced by the two contacts C50 and C51. Two contacts provide four different binary states:

S both off S C50 on and C51 off S C50 off and C51 on S both on

We only need to use three of the four binary states (circled) since we only have three RX/WX instructions to sequence.

Truth Table C52 C51 C50 First RX/WX 0 0 0 Second RX/WX 0 0 1 Third RX/WX 0 1 0 Fourth RX/WX 0 1 1 Fifth RX/WX 1 0 0 Sixth RX/WX 1 0 1 Seventh RX/WX 1 1 0 Eighth RX/WX 1 1 1

First RX/WX Instruction

Guidelines

User Application

RLL Programming

for Communications

C50 and C51 are interlocking contacts. They are normally closed in this rung to permit power flow to the first WX instruction. Both bits are off, corresponding to the first row of the truth table.

After the WX instruction is executed C50 is SET (turned on) which opens the contact in this rung and closes the C50 contact in the next rung.

C51 is RESET (turned off) which leaves the C51 contact closed for the next rung.

SP122

C51

C50

LD K214

LD K2

LDA O40600

WX VC100

C50

SET

C51

RST

DL05/06 Data Communications Module, 1st Edition, 08/05

RLL Programming for Communications

4–15

Second RX/WX Instruction

Third RX/WX Instruction

C50 is normally open and C51 is normally closed. For this rung to be executed, the C50 bit must be on and the C51 bit must be off, corresponding to the second row of the truth table. C50 was turned on in the previous rung. C51 was turned off in the previous rung.

After the WX instruction is executed C50 is RESET (turned off) which opens the C50 contact in this rung and closes it in the next rung.

C51 is SET (turned on), which closes the normally open C51 contact in the next rung.

In this last rung, C50 is normally closed and C51 is normally open. For this rung to be executed, the C50 bit must be o f f and the C51 bit must be on, corresponding to the third row of the truth table. C51 was turned on in the previous rung.

After the RX instruction is executed, C50 is RESET which opens the C50 contact in this rung and allows it to close in preparation for repeating the first communication rung on the next CPU scan (page 4-14).

SP122

C51

C50

LD K209

LD K2

LDA O40601

WX VC0

C50

RST

C51

SET

LD K214

LD K2

LDA O40602

RX VC20

C50

RST

User Application

Guidelines

for Communications

RLL Programming

Returning to the First RX/WX Instruction

C51 is also RESET, which allows the

C51

RST

C51 contact to close in preparation for repeating the first communication rung on the next CPU scan (page 4-14).

At the end of the third RX/WX instruction, we cycle back to the top row of the truth table on page 4–14. Both C50 and C51 are off, and the next CPU scan executes the first RX/WX instruction.

DL05/06 Data Communications Module, 1st Edition, 08/05

4–16

RLL Programming for Communications

Shift Register

Getting Started

The Shift Register can be used for creating interlocks, as an alternative to using control relays. For a complete explanation of the function of the Shift Register, see the User Manual for your PLC. If you have more than a few RX/WX instructions, using control relays can become cumbersome. The Shift Register allows a single contact to be used in each communication rung as an interlock.

The data input to the Shift Register

SP1

(SR) is Special Relay SP1. SP1 is the always-on bit. Combined with a

SP122

normally closed contact it sends zeros to the Shift Register data input.

The clock input to the Shift Register is

C63

SP122, the communication busy bit. Each time one of the RX/WX instructions executes, the Shift Register moves the set bit over one place.

C63 is used in this example to reset the Shift Register to all zeros.

C60

C77

Guidelines

User Application

RLL Programming

for Communications

Store If Equal

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after first scan.

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after second scan.

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after first RX/WX.

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after second RX/WX.

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after third RX/WX.

C74 C73 C72 C71 C70 C67 C66 C65 C64 C63 C62 C61 C60C75C76C77

Shift Register after third RX/WX plus one scan.

The Store If Equal instruction detects when the Shift Register is reset to zeros. When that condition is true the C60 bit is SET by this rung. The C60 bit becomes the high bit shifted by the Shift Register until each RX/WX instruction is executed in turn.

V40603

C60

SET

DL05/06 Data Communications Module, 1st Edition, 08/05

First RX/WX Instruction

4–17

RLL Programming for Communications

Second RX/WX Instruction

C60 is the interlocking contact. It is turned on by the Store If Equal rung preceding this one.

C61 is the interlocking contact. It is turned on by the sequencing steps of the Shift Register in a preceding rung.

SP122

C60

C61

LD K214

LD K2

LDA O40600

WX VC100

LD K209

LD K2

User Application

Guidelines

Third RX/WX Instruction

LDA O40601

WX VC0

C62 is the interlocking contact. It is turned on by the sequencing steps of

SP122

C62

LD K214

the Shift Register in a preceding rung.

LD K2

LDA O40602

RX VC20

After this rung is executed, the Shift Register shifts the high bit from C62 to C63 on the next CPU scan. C63 resets the Shift Register to zeros, the Store If Equal sets the C60 bit, and the CPU executes the first RX/WX instruction.

for Communications

RLL Programming

DL05/06 Data Communications Module, 1st Edition, 08/05

D0–DCM Using

MODBUS

In This Chapter. . . .

— Network Slave Operation — Network Master Operation

RTU

5–2

D0–DCM Using MODBUS

Network Slave Operation

This section describes how a MODBUS RTU master on a network can communicate with a D0–DCM using the MODBUS RTU protocol. A network master must send a MODBUS function code and MODBUS address to specify a PLC memory location in the DL05/06 CPU. No CPU ladder logic is required to support MODBUS slave operation.

MODBUS Function Codes Supported

Determining the MODBUS Address

The D0–DCM supports the following MODBUS function codes when acting as a MODBUS slave.

MODBUS

Function Code

01 Read Output Table Y, C, T, CT 02 Read Input Table X, SP 03 Read Holding Registers (when addressing

mode is 584/984, this function is used to access analog output registers)

04 Read Input Registers (when addressing mode

is 584/984, this function is used to access

analog input registers) 05 Force Single Output Y, C, T, CT 06 Preset Single Registers V 08 Loop back / Maintenance 15 Force Multiple Outputs Y, C, T, CT 16 Preset Multiple Registers V

Function DL05/06

Data Types Available

There are typically two ways that most MODBUS addressing conventions allow you to specify a PLC memory location. These are:

• By specifying the MODBUS data type and address

• By specifying a MODBUS address only.

D0–DCM with

MODBUS RTU

DL05/06 Data Communications Module, 1st Edition, 08/05

D0–DCM Using MODBUS

5–3

If Your Host Software or Master Requires the Data Type and Address

Many MODBUS masters allow you to specify the MODBUS data type and the MODBUS address that corresponds to the PLC memory location. This is the easiest method, but not all packages allow you to do it this way.

The actual equation used to calculate the address depends on the type of PLC data you are using. The PLC memory types are split into two categories for this purpose.

• Discrete – X, SP, Y, C, S, T(contacts), CT (contacts)

• Word – V memory, Timer current value, Counter current value

In either case, you basically convert the PLC octal address to decimal and add the appropriate MODBUS starting address (as required). The following tables show the exact range used for each group of data.

For an automated MODBUS/Koyo address conversion utility, download the file modbus_conversion.xls from the www.automationdirect.com technical support website > Technical and Application notes> PLC hardware> Coummunications

AN–MISC–010.

DL05 Memory Type QTY

(Dec.)

For Discrete Data Types .... Convert PLC Addr. to Dec. + Start of Range + Data Type

Inputs (X) 256 X0 – X377 2048 – 2303 Input Special Relays (SP) 512 SP0 – SP777 3072 – 3583 Input Outputs (Y) 256 Y0 – Y377 2048 – 2303 Coil Control Relays (C) 512 C0 – C777 3072 – 3583 Coil Timer Contacts (T) 128 T0 – T177 6144 – 6271 Coil Counter Contacts (CT) 128 CT0 – CT177 6400 – 6527 Coil Stage Status Bits (S) 256 S0 – S377 5120 – 5375 Coil

PLC Range

(Octal)

MODBUS

Address Range

> app note #

MODBUS

Data Type

For Word Data Types .... Convert PLC Addr. to Dec. + Data Type

Timer Current Values (V) 128 V0 – V177 0 – 127 Input Register Counter Current Values (V) 128 V1000 – V1177 512 – 639 Input Register V Memory, user data (V) 3072 V1400 – V7377 768 – 3839 Holding Register

DL05/06 Data Communications Module, 1st Edition, 08/05

MODBUS RTU

D0–DCM withInstallation and

5–4

D0–DCM Using MODBUS

DL06 Memory Type QTY

(Dec.)

For Discrete Data Types .... Convert PLC Addr. to Dec. + Start of Range + Data Type

Inputs (X) 512 X0 – X777 2048 – 2560 Input Special Relays (SP) 512 SP0 – SP777 3072 – 3583 Input Outputs (Y) 512 Y0 – Y777 2048 – 2560 Coil Control Relays (C) 1024 C0 – C1777 3072 – 4095 Coil Timer Contacts (T) 256 T0 – T377 6144 – 6399 Coil Counter Contacts (CT) 128 CT0 – CT177 6400 – 6527 Coil Stage Status Bits (S) 1024 S0 – S1777 5120 – 6143 Coil Global Inputs (GX) 2048 GX0 – GX3777 0 – 2047 Input Global Outputs (GY) 2048 GY0 – GY3777 0 – 2047 Coil

For Word Data Types .... Convert PLC Addr. to Dec. + Data Type

Timer Current Values (V) 256 V0 – V377 0 – 255 Input Register Counter Current Values (V) 128 V1000 – V1177 512 – 639 Input Register V Memory, user data (V) 256

3072 4096

PLC Range

(Octal)

V400 – V677 V1400 – V7377 V10000 – V17777

MODBUS

Address Range

256 – 511 768 – 3839

4096 – 8191

MODBUS

Data Type

Holding Register

D0–DCM with

MODBUS RTU

DL05/06 Data Communications Module, 1st Edition, 08/05

5–5

D0–DCM Using MODBUS

The following examples show how to generate the MODBUS address and data type for hosts which require this format.

Example 1: V2100

Example 2: Y20

Find the MODBUS address for User V location V2100.

1. Find V memory in the table.

2. Convert V2100 into decimal (1089).

3. Use the M ODBUS d ata t ype f rom t he t able.

Find the MODBUS address for output Y20.

1. Find Y outputs in the table.

2. Convert Y20 into decimal (16).

3. Add the starting address for the range (2049).

4. Use the M ODBUS d ata t ype f rom t he t able.

PLC Address (Dec.) + Data Type

V2100 = 1088 decimal 1088 + Hold. Reg. = Holding Reg. 1089

PLC Addr. (Dec) + Start Addr. + Data Type

Y20 = 16 decimal 16 + 2049 + Coil = Coil 2065

Example 3: T10 Current Value

Example 4: C54

Find the MODBUS address to obtain the current value from Timer T10.

1. Find Timer Current V alues in the table.

2. Convert T10 into decimal (8).

3. Use the M ODBUS d ata t ype f rom t he t able.

Find the MODBUS address for Control Relay C54.

1. Find Control Relays in the table.

2. Convert C54 into decimal (44).

3. Add the starting address for the range (3072).

4. Use the M ODBUS d ata t ype f rom t he t able.

PLC Address (Dec.) + Data Type

TA10 = 8 decimal 8 + Input Reg. = Input Reg. 8

PLC Addr. (Dec) + Start Addr. +Data Type

C54 = 44 decimal 44 + 3073 + Coil = Coil 3117

MODBUS RTU

D0–DCM withInstallation and

DL05/06 Data Communications Module, 1st Edition, 08/05

5–6

D0–DCM Using MODBUS

If the Host Software or Master Requires an Address ONLY

Inputs (X) 256 X0 – X377 12049 – 12304 Special Relays (SP) 512 SP0– SP777 13073 – 13584 Reserved – – 13585 – 20000 Outputs (Y) 256 Control Relays (C) 512 Timer Contacts (T) 128 T0 – T177 6145 – 6272 Counter Contacts (CT) 128 CT0 – CT177 6401 – 6528 Stage Status Bits (S) 256 S0 – S377 5121 – 5376 Reserved – – 6529 – 10000

Some MODBUS masters do not allow you to specify the MODBUS data type and address. Instead, you specify an address only. This method requires another step to determine the address, but it is not difficult. Basically, MODBUS also separates the data types by address ranges as well. This means an address alone can actually describe the type of data and location. This is often referred to as “adding the offset”.

The actual equation used to calculate the address depends on the type of PLC data you are using. The PLC memory types are split into two categories for this purpose.

• Discrete – X, GX, SP, Y, C, S, T, CT (contacts)

• Word – V memory , Timer current value, Counter current value

> app note #

AN–MISC–010.

DL05 Discrete Data Types

PLC Memory Type

QTY (Dec.)

PLC Range

(Octal)

Y0 – Y377

C0 – C777

MODBUS Address

Range

2049 – 2304 3073 – 3584

Access

Read

only

Read/

Write

Registers

QTY (Dec.)

3072 V1400 – 7377 40769 – 43840 30769 – 33840

V Memory (Timers) 128 V0 – V177 40001 – 40128 30001 – 30128 Read/

V Memory (Counters) 128 V1000 – V1177 40513 – 40640 30513 – 30640 V Memory (Data

Words)

D0–DCM with

MODBUS RTU

(Word)

DL05/06 Data Communications Module, 1st Edition, 08/05

DL05 Word Data Types

PLC Range

(Octal)

MODBUS 40001

Address Range

MODBUS 30001

Address Range

Access

Write

Read/

Write

PLC Memory Type

DL06 Discrete Data Types

QTY (Dec.)

D0–DCM Using MODBUS

PLC Range

(Octal)

MODBUS Address

Range

5–7

Access

Global Inputs (GX) 2048

Inputs (X) 512 X0 – X777 12049 – 12560 Special Relays (SP) 512 SP0– SP777 13073 – 13584 Reserved – – 13585 – 20000

Global Outputs (GY) 2048 GY0– GY3777 1 – 2048 Outputs (Y) 512 Control Relays (C) 1024 Timer Contacts (T) 256 T0 – T377 6145 – 6400 Counter Contacts (CT) 128 CT0 – CT177 6401 – 6528 Stage Status Bits (S) 1024 S0 – S1777 5121 – 6144 Reserved – – 6529 – 10000

DL06 Word Data Types

Registers

(Word)

V Memory (Timers) 256 V0 – V377 40001 – 40256 30001 – 30256 Read/

V Memory (Counters) 128 V1000 – V1177 40513 – 40640 30513 – 30640 Read/

V Memory (Data Words)

QTY (Dec.)

256 V400 – V777 40257 – 40512 30257 – 30512 3072 V1400 – 7377 40769 – 43840 30769 – 33840 4096 V10000 – V17777 44097 – 48192 34097 – 38192

PLC Range

(Octal)

GX0–GX1746 10001 – 10999

GX1747 – GX3777 11000 – 12048

Y0 – Y777

C0 – C1777

MODBUS 40001

Address Range

2049 – 2560 3073 – 4096

MODBUS 30001

Address Range

Read

only

Read/

Write

Access

Write

Read/

Write

DL05/06 Data Communications Module, 1st Edition, 08/05

MODBUS RTU

D0–DCM withInstallation and

5–8

D0–DCM Using MODBUS

Example 1: V2100

Example 2: Y20

Find the MODBUS address for User V location V2100.

1. Find V memory in the table.

2. Convert V2100 into decimal (1088).

3. Add the MODBUS starting address for the mode (40001).

Find the MODBUS address for output Y20.

1. Find Y outputs in the table.

2. Convert Y20 into decimal (16).

3. Add the starting address for the range (2048).

4. Add the MODBUS address for the mode (1).

PLC Address (Dec.) + Mode Address

V2100 = 1088 decimal 1088 + 40001 = 41089

PLC Addr. (Dec) + Start Address + Mode

Y20 = 16 decimal 16 + 2048 + 1 = 2065

Example 3: C54

D0–DCM with

MODBUS RTU

Find the MODBUS address for Control Relay C54.

1. Find Control Relays in the table.

2. Convert C54 into decimal (44).

3. Add the starting address for the range (3072).

4. Add the MODBUS address for the mode (1).

PLC Addr. (Dec) + Start Address + Mode

C54 = 44 decimal 44 + 3072 + 1 = 3117

DL05/06 Data Communications Module, 1st Edition, 08/05

Network Master Operation

This section describes how the DL05/06 CPU can serve as a master on a MODBUS RTU network using the D0–DCM. This section discusses how to design the required ladder logic for network master operation.

5–9

D0–DCM Using MODBUS

MODBUS Slaves

MODBUS Function Codes Supported

Slave #1 Slave #3

Master

MODBUS RTU Protocol

When using the DCM as a master on the network, you use simple RLL instructions to

Slave #2

Master

initiate the requests. The WX instruction initiates network write operations, and the RX instruction initiates network read operations. Before executing either the WX or RX commands, we need to load data related to

Slave

the read or write operation onto the CPU’s accumulator stack. When the WX or RX instruction executes, it uses the information on the stack combined with data in the instruction box to completely define the task.

WX (write) RX (read)

Network

The D0–DCM supports the following MODBUS function codes when acting as a MODBUS RTU master.

MODBUS

Function Code

01 Read Output Table Y, C, T, CT 02 Read Input Table X, SP 03 Read Holding Registers (when addressing

mode is 584/984, this function is used to ac-

cess analog output registers) 06 Preset Single Registers V 15 Force Multiple Outputs Y, C, T, CT 16 Preset Multiple Registers V

Function DL05/06

Data Types Available

Note: The D0–DCM, as a master, does not support function code 4. Thus, 30001 address ranges cannot be read from a slave device.

DL05/06 Data Communications Module, 1st Edition, 08/05

MODBUS RTU

D0–DCM withInstallation and

5–10

PLC Memory Supported for Master Operation

D0–DCM Using MODBUS

The actual equation used to calculate the address depends on the type of PLC data you are using. The PLC memory types are split into three categories for this purpose.

• Discrete – X, GX, SP

• Discrete – Y, C, S, T, CT

• Word – Timer current value, Counter current value, Data Words

In either case, you basically take the MODBUS address you are trying to target, subtract the starting MODBUS of that range, convert the result to octal and add the octal number to the begining PLC address in the appropriate PLC range. See the conversion examples on the following page. The following tables show the exact range used for each group of data.

AN–MISC–010.

PLC Memory Type

DL06 Discrete Data Types*

QTY (Dec.)

PLC Range

(Octal)

> app note #

MODBUS Address

Range

Access

D0–DCM with

MODBUS RTU

Global Inputs (GX) 2048

Inputs (X) 512 X0 – X777 12049 – 12560 Special Relays (SP) 512 SP0– SP777 13073 – 13584 Reserved – – 13585 – 20000

DL06 Word Data Types*

Registers

(Word)

V Memory (Timers) 256 V0 – V377 40001 – 40256 Read/

V Memory (Counters) 128 V1000 – V1177 40513 – 40640 Read/

V Memory (Data Words)

QTY (Dec.)

256 V400 – V777 40257 – 40512 3072 V1400 – 7377 40769 – 43840 4096 V10000 – V17777 44097 – 48192

GX0–GX1746 10001 – 10999

GX1747 – GX3777 11000 – 12048

Y0 – Y777

C0 – C1777

PLC Range

(Octal)

2049 – 2560 3073 – 4096

MODBUS Address

Range

Read

only

Read/

Write

Access

Write

Read/

Write

* Refer to page 5–6 for memory mapping size for the DL05 CPUs. The DL06 has a larger memory in some areas.

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D0–DCM Using MODBUS

Your PC’s Windows calculator can be used for number conversions (i.e. decimal to octal). The Windows calculator must be in Calculator>View>Scientific mode to enable number conversions capability.

Example 1: Calculating Word PLC Address

Example 2: Calculating Discrete Input PLC Address

Find the PLC address to use to target MODBUS address 41025 in a server device.

1. Subtract the begining of the MODBUS word address range (40001) from the desired MODBUS address to target.

2. Convert decimal result into octal.

3. Add octal result to begining PLC range (Input, Output or Word).

Find the PLC address to use to target MODBUS address 12060 in a server device.

1. Subtract the begining of the MODBUS Input address range (12049) from the desired MODBUS address to target.

2. Convert decimal result into octal.

3. Add octal result to begining PLC range (Input, Output or Word).

1. 41025 – 40001 = 1024 decimal

2. 1024 decimal = 2000 octal

3. V0 (octal) + 2000 (octal) = V2000 octal

1. 12060 – 12049 = 11 decimal

2. 11 decimal = 13 octal 3 X0 (octal) + 13 (octal) = X13 octal

DL05/06 Data Communications Module, 1st Edition, 08/05

MODBUS RTU

D0–DCM withInstallation and

5–12

D0–DCM Using MODBUS

Building the Read (RX) or Write (WX) Routine

Step 1: Identify DCM Slot Location and Slave

For network communications, you build the Read (RX) or Write (WX) instructions into a routine which requires the four instructions you see to the right. They must be used in the sequence shown. The following step-by-step procedure will provide you the information necessary to set up your ladder program to receive data from a network server.

The first Load (LD) instruction accepts either a constant or a variable. Use a “K” to designate the number as a constant. Use a “V” if you are entering the address of a register. The contents of that register perform the same function as the constant shown below. For example, you could use V2000 in place of K0114. If the contents of V2000 is the number “114,” the function would be the same. Using a variable allows changing parameters while the program is running.

Lower Byte

1140

Master PLC

Upper Byte

A aaa

LDA

O aaa

RX or WX

A aaa

K114

Slave device

D0–DCM with

MODBUS RTU

DCM Slot #

DL05 Special Relays

Relay Option Slot Communication busy SP120

Communication error SP121

DL06 Special Relays

Relay Slot 1 Slot 2 Slot 3 Slot 4 Communication busy SP120 SP122 SP124 SP126

Communication error SP121 SP123 SP125 SP127

Slave Address #

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Step 2: Load Number of Bytes to Transfer

Step 3: Specify Master Memory Area

The second Load (LD) instruction determines the number of bytes which will be transferred between the master and slave in the subsequent WX or RX instruction. The value to be loaded is in BCD format (decimal), from 1 to 128 bytes.

The third instruction in the RX or WX sequence is a Load Address (LDA) instruction. Its purpose is to load the starting address of the memory area to be transferred. Entered as an octal number, the LDA instruction converts it to hex and places the result in the accumulator.

For a WX instruction, the DL05/06 CPU sends the number of bytes previously specified from its memory area beginning at the LDA address specified.

For an RX instruction, the DL05/06 CPU reads the number of bytes previously specified from the server, placing the received data into its memory area beginning at the LDA address specified.

1 2 8

(BCD)

# of bytes to transfer

LD K128

6 0 00

(octal)

Starting address of client transfer area

LDA O40600

MSB LSB

V40600

V40601

015

Note: Since V memory words are always 16 bits, you may not always use the whole word. For example, if you only specify to read 3 bytes, you will only get 24 bits of data. In this case, only the 8 least significant bits of the last word location will be modified. The remaining 8 bits are not affected.

Step 4: Specify Slave Memory Area

The last instruction in our sequence is the WX or RX instruction itself. Use WX to write to the server, and RX to read from the server. All four of our instructions are shown to the right. In the last instruction, you must specify the starting address and a valid data type for the server.

SP122

LD K114

LD K128

LDA O40600

RX V0

MODBUS RTU

D0–DCM withInstallation and

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D0–DCM Using MODBUS

Communications from a Ladder Program

Typically network communications will last longer than 1 scan. The program must

SP121

SET

wait for the communications to finish before starting the next transaction.

DCM Communication Error

SP120

DCM Port Busy

LD K114

LD K3

LDA O40600

RX V0

Depending on which slot the DCM is in, it has two Special Relay contacts associated with it (see page 5–12 for special relays). One indicates “Port busy”, and the other indicates “Port Communication Error”. The example above shows the use of these contacts for an ECOM that is in slot 1. The “Port Busy” bit is on while the PLC communicates with the slave. When the bit is off the program can initiate the next network request.

The “Port Communication Error” bit turns on when the PLC has detected an error. Use of this bit is optional. When used, it should be ahead of any network instruction boxes since the error bit is reset when an RX or WX instruction is executed.

Multiple Read and Write Interlocks

D0–DCM with

MODBUS RTU

If you are using multiple reads and writes in the RLL program, you have to interlock the routines to make sure all the routines are executed. If you don’t use the interlocks, then the CPU will only execute the first routine. This is because each port can only handle one transaction at a time.

In the example to the right, after the RX instruction is executed, C0 is set. When the port has finished the communication task, the second routine is executed and C0 is reset.

PLUS

If you are using RLL

Stage Programing, you can put each routine in a separate program stage to ensure proper execution and switch from stage to stage allowing only one of them to be active at a time.

SP120

C100

Interlocking

Relay

C100

Interlocking Relay

LD K114

LD K3

LDA O40600

RX V0

C100

SET

LD K114

LD K3

LDA O40400

WX V0

C100

RST

DL05/06 Data Communications Module, 1st Edition, 08/05

Automation Direct D0–DCM User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual