Chapter 11 Introduction to Device Net Device Net

Chapter 11 Introduction to Device. Net

Device. Net Purpose • Open network • Link low-level devices to PLCs – Sensors – Pushbutton stations – Distributed I/O blocks – Intelligent motor started overloads – Variable frequency drives

Device. Net Open Network • Open network • Network devices (nodes) can be purchased from many different vendors • Network managed by Open Device. Net Vendors Association (ODVA) – ODVA. ORG

Device. Net Advantage • Save wiring costs – Rather than run power wires separately to each device – Rather than run signal wires from each field device separately back to PLC, I/O module connect devices directly to a network – One cable with four wires • Two power wires • Two signal wires

Field Devices More Intelligent • Traditional systems – A photo switch counting pieces as they pass on a conveyer was wired directly into an input module. • Counter programmed on ladder to track parts’ count • Counter done bit triggered output point to control field action

Device. Net Advantage • Many Device. Net devices are intelligent. • Photo switch has counters and timers incorporated into sensor. • PLC does not need to have timer or counter on ladder. • When timer or counter is done, the action is carried out through RSNet. Worx for Device. Net software to trigger field device across the network.

Device. Net Components • • PLC with Device. Net scanner RSNet. Worx software for Device. Net Trunk line Drop lines Nodes Minimum one power supply Two 121 -ohm ¼-watt termination resistors Up to 64 nodes

Device. Network Example Prox switch and cable Stack light Cable to open-style connector on network PLC scanner Kwik. Link cable Power supply Termination resistor Right. Sight photo sensor Termination resistor Insulation displacement connector Armor. Block maximum 4 I/O points Open-style connection Compact. Block for power supply I/O module

Sample of Some Device. Net Media Components Thick round drop line cable Kwik. Link flat trunk line cable insulation displacement connector Device port T-port Kwik. Link flat trunk line cable Device. Link

Device. Net Cabling • • • Thick round Thin round Kwik. Link cable Special-use cable Open-style connectors

Thick Round Cable • Used for trunk line • T-ports used to connect from trunk line to drop lines

Thin Round Cable • Typically used for drop lines • Can be used for trunk in short networks with low current requirements

Kwik. Link Device. Net Connection Insulation displacement connector Kwik. Link flat cable

Insulation Displacement Connection • For non-wash down • Typical usage conveyor lines • Mount on inside rail of conveyor • No conduit needed • Easy installation of new nodes • No minimum spacing

Device. Port • • Passive 4 - or 8 -point taps Connected to trunk line by drop line Previous slide showed an 8 -point Device. Port Nodes connected to Device. Port by drop lines

T-port • Used to connect drop line to trunk line • Drop line connected to Device. Port and then on to multiple nodes • Drop line connected directly to node • Maximum drop line length 20 feet

Device. Link • Adapter to interface non-Device. Net devices to network • 2 - or 3 -wire 24 -V sensors • Mechanical limit switches • Any non-Device. Net device with relay contacts • One required for each non-Device. Net node

Additional Media • Refer to the Device. Net Media catalog for a complete listing of available products.

Maximum Trunk Line Length (1 of 2) • Maximum cable distance between any two nodes • Not necessarily actual length of backbone • Maximum length determined by cable type and baud rate

Maximum Trunk Line Length (2 of 2)

Trunk Line Calculation One Node number

Example One • Left terminating resistor to node 1 is 12 feet. • Drop line node 1 is 2 feet. • Right terminating resistor to node 12 is also 12 feet. • Node 12 drop line is 2 feet. • From node 1 drop line to node 12 drop line is 800 feet.

Trunk Line Calculation (1 of 2) • For this example, trunk line length is maximum length of cable between terminating resistors.

Trunk Line Calculation (2 of 2) • 12 + 800 + 12 = 824 feet • Refer to table for maximum baud rate of network.

Maximum Trunk Line Length Trunk line length is over 820 feet so maximum baud rate for this network is 125 K.

Trunk Line Calculation Two Power Supply 300 ft 2 ft 3 ft 11 6 ft 7 3 1 6 4 2 5 8 8 ft 12 ft 9 12 13 10 Node numbers 14

Example Two • Left terminating resistor to node 1 drop line is 20 feet. • Node 1 drop line is 6 feet. • Right terminating resistor to node 12 drop line is 2 feet. • Node 12 drop line is 8 feet. • Trunk line from node 12 drop to node 14 drop line is 3 feet. • Node 14 drop line is 12 feet. • Node 1 trunk line to node 14 is 300 feet.

Trunk Line Calculation • For this example, trunk line length is maximum length of cable between any two nodes or terminating resistors. • Assume round thick trunk line. • Look at network again.

Trunk Line Calculation Two (1 of 2) Power Supply 300 ft 2 ft 3 ft 11 6 ft 7 3 1 6 4 2 5 8 8 ft 12 ft 9 12 13 10 14 For this example, trunk line length is maximum length of cable between any two nodes or terminating resistors.

Trunk Line Calculation Two (2 of 2) • The longest cable distance is between the left terminating resistor and node 14. • For this example, the distance between terminating resistors would not be the correct calculation. • 20 + 300 + 12 = 332 feet • Refer to table for maximum baud rate of network.

Maximum Trunk Line Length (1 of 3) Trunk line length is over 328 feet so maximum baud rate for this network is either 125 K or 250 k.

Maximum Trunk Line Length (2 of 3) • The rule is to go back 20 feet from the termination resistors and see if there is a drop line that is longer. – If a drop is longer, then it must be included in the trunk line calculation. – Remember maximum drop line length is 20 feet.

Maximum Trunk Line Length (3 of 3) • Terminating resistor and node 00 is 3 feet. • Node 00 and node 1 is 4 feet. • Trunk line to node 7 is 15 feet. • 15 foot drop is longer than 3 +4 for trunk. 7 8 15 3 4 20 feet

Cumulative Drop Line Length (1 of 2) • Sum of all drop lines • Maximum drop line length to any one node – 20 feet • Cumulative drop line length also determines network baud rate

Text figure 11 -30 Cumulative Drop Line Length (2 of 2)

Total All Drop Line Lengths (1 of 2)

Total All Drop Line Lengths (2 of 2) • Cumulative length is 131 feet. • Nodes 10, 13, and 14 exceed the 20 -foot maximum drop to any 1 node. • Shorten up cable. • Cumulative drop line length is now 127 feet. • Refer to the table for maximum baud rate for network.

Cumulative Drop Line Length Cumulative drop line length is 127 feet.

Power Calculations • • • Add up total device current Determine trunk line length Cable type How many power supplies and where mounted Look up tables for power allowed on network Full calculation method available for additional accuracy

Common Problems With Device. Networks (1 of 2) • Improper installation – – Trunk line length correct? Cumulative drop line length correct? Power supply proper size? Overdriving network with too much information flow? • Refer to Device. Net Cable System Planning and Installation Manual from Rockwell Automation Web site.

Common Problems With Device. Networks (2 of 2) • Network modification after installation – Trunk line length recalculated? – Cumulative drop line length recalculated? – Power supply recalculated? – Overdriving network with too much information flow?

Device. Net Interface

Flex. Logix PLC Device. Net Daughter Card Device. Net open-style cable connection point Set baud rate Status LEDs Set interface card’s node

Compact. Logix Device. Net Scanner Device. Net scanner Open-style cable connection Compact. Logix processor Compact. Logix is a member of the Control. Logix family.

Control. Logix Modular Interface 1756 -DNB • Control. Logix modular chassis interface module • 1756 -DNB • Device. Net bridge module Information window Status LEDs Open-style network connection

Example of Rockwell Automation PLC Device. Net Interface Modules • SLC 500 Device. Net scanner – 1747 -SDN • PLC 5 Device. Net scanner – 1771 -SDN

Example of General Electric PLC Device. Net Interface Modules • Series 90 -30 PLCs – Device. Net master module – IC 693 DNM 200 • Versa. Max PLC – Remote I/O Device. Net network interface – IC 200 DB 1001

Personal Computer Device. Net Interface • Computer type determines interface needed. – Notebook uses PCMCIA such as a Rockwell Automation 1784 -PCD. – Desktop or industrial computer would require a Device. Net 1784 -expansion card. – Computer with serial port could use Rockwell Automation 1770 -KFD interface box.

1770 -KFD Interface Desktop or notebook computer with serial port SLC 500 1747 -SDN Interface cable plug KFD to serial port interface cable 1770 -KFD Interface cable Open-style connector to Device. Net network

1784 -PCD Card SLC 500 1747 -SDN Notebook personal computer PCMCIA interface card 1784 -PCD Interface cables Open-style connector to Device. Net network

Use Control. Logix PLC as a Bridge (1 of 2) • Most popular interface to PLC for upload, download, on-line editing is Ethernet • Ethernet interface card in Control. Logix chassis(1756 - ENBT) • A 1756 -DNB or Device. Net bridge module in Control. Logix chassis to communicate with Device. Net

Use Control. Logix PLC as a Bridge (1 of 2) • Use RSLinx Ethernet driver to get to Ethernet interface module • Bridge across Control. Logix backplane to Device. Net Bridge module (1756 -DNB) • Out DNB to Device. Net network • No separate Device. Net interface required

RSNet. Worx Software • RSNetworx for Device. Net software – Set up network – Map data flowing on network – Program, monitor, or modify device parameters

RSNet. Worx for Device. Net

RSNet. Worx View of Device. Network scanner Drop line Termination resistor Node address Trunk line Device or node on network Power supply not shown in RSNet. Worx

Device. Net Scan List • RSNet. Worx software • Scan List is part of scanner properties. • Any device that is on the network that is to be scanned by the PLC scanner must be in the Scan List. • Network devices are not mapped until placed in the Scan List by programmer. – Auto mapping – Manual mapping

Device. Net PLC Scanner Properties Control. Logix DNB scanner properties screen Add or remove single device to or from Scan List Add or remove all devices to or from Scan List Auto map devices when add to scan list Scan List tab Scan List Electronic keying

Available Devices on Network • When going on-line with a network scanner, like a 1756 -DNB, scanner will recognize devices currently present on network. – These devices or nodes will be listed in the Available Devices view. – These devices are not in the scan list at this time.

Auto Map Devices When Add to Scan List • Do you want the device(s) to be auto-mapped when added to the scan list? • If Automap is selected, you have no control of how devices are mapped. • If you uncheck Automap, then devices can be manually mapped by the programmer.

Electronic Keying • How close does a replacement device have to be to the original when replaced? – Device type – Vendor – Product code – Major revision – Minor revision • Minor revision or higher

Device. Net Data Mapping Control. Logix

Control. Logix 1756 -DNB Mapping Input tab Scanner properties Click here to unmap a device. Input devices in Scan List Unused processor memory. Can be manually mapped later. Data mapping for each node Control. Logix processor tags or addresses where data is mapped.

Device. Net Data Mapping • Control. Logix is a 32 -bit PLC. – All tags will be either 32 bits wide or a: • Word, called an integer (INT) which is 16 bits • Byte, called a short integer (SINT) which is 8 bits • Minimum memory allocation for any Device. Net device is a SINT. • Node 6 is a bulletin 160 Allen-Bradley Drive. – Drive has two words of data. • Drive status information as single bits • Drive speed feedback represented as 0 to 32767

Control. Logix Input Mapping 32 Bits 16 Bits 31 Control. Logix Tags Node 6 Drive Input Status word Node 6 Drives Speed Feedback word 16 15 8 7 0 Node 3 Series 9000 Photo Electric Sensor mapping Node 4 Series 9000 Photo Electric Sensor mapping

Control. Logix Processor Data Mapping or Tags (1 of 2) • Node 6 is Bulletin 160, the variable frequency drive – Status bits mapped as upper word of Local: 1: I. Data[2]. – Drive Speed Feedback word is mapped as the lower word of Local: 1: I. Data[3].

Control. Logix Processor Data Mapping or Tags (2 of 2) • Node 4 is a Series 9000 Photo Switch mapped as the upper byte of the lower word at Local: 1. I. Data[2]. • Node 3 is a Series 9000 Photo Switch mapped as the lower byte of the lower word at Local: 1. I. Data[2].

Device. Net Data Mapping SLC 500

Device. Net Data Mapping • SLC 500 and PLC 5 are 16 -bit computers. – All data will either be a 16 -bit word or one byte. • Minimum memory allocation for any Device. Net device is a byte. • Node 6 is a Bulletin 160 Allen-Bradley Drive. – Drive has two words of data. • Drive Command information as single bits • Drive Speed Command represented as 0 to 32767

SLC 500 Output Data Mapping 1747 -SDN properties view Output devices in Scan List SLC 500 Output Status Table where data is coming from Output mapping tab Click here to unmap selected device Two words or 8 bytes currently mapped for drive at node 6

SLC 500 Processor Data Mapping • Node 6 is Bulletin 160, the variable frequency drive – Drive Command bits word is mapped as O: 1. 2. – Drive Speed Command word is mapped as O: 1. 3.

Node 2 Output Mapping • Node 8 is a Rockwell Automation 1792 D compact block output module. – This compact block has four outputs. • Output data from SLC 500 mapped to lower byte of O: 1. 6. • Currently upper byte of O: 1. 6 is available for another device.

Device. Net Nodes General Properties

• Right click on device on RSNet. Worx screen. • General Properties screen is displayed. – Display I/O data – Display, monitor, or modify devices parameters – View electronic data sheet (EDS file)

General Properties Parameters tab EDS tab Identifies this device Current node address. Node address can be changed here. Device’s identity Numbers used to identify EDS file

Device Parameters tab Lock identifies read-only parameters Parameter number Monitor a single parameter or all Icons for uploading or downloading to device Click here to monitor parameter Current value of parameter

Parameter Editing Select parameter to edit Options drop-down box Select

Electronic Data Sheets EDS Files

Electronic Data Sheets • Typically referred to as EDS files – EDS files contain information regarding the personality of the device. – Correct EDS file must reside in the device before it can be a working part of the network. – EDS file must be the same firmware level as the device.

If EDS File Is Not Current • Go to manufacturer’s Web site and download correct file. • Go to ODVA. ORG site and download correct file. • EDS file numbers represented in Hex. • Use EDS Wizard to update or register the network device.

EDS Wizard Updating a network Device’s EDS file is to register the file. Click next to continue.

Register EDS File How many files to register After download, browse for file on you computer. EDS file name represented in Hex Click next to continue registration.

Determine EDS File Name • After downloading EDS file, the file name is represented in Hex. – To determine EDS file to use when registering file: • Must know Hex • Construct file number from RSNet. Worx general properties page

Convert General Properties Page Device Identity to Hex [1] = 0001 [6] = 0006 [43] = 002 B [1. 004] = 0100

Select Correct EDS File

Select Correct EDS File