Instruction Manual

Watlow EZ-ZONE
®
PM Limit Controller • 82 • Chapter 8 Features
CIP - Communications Capabilities
With the introduction of CIP a user can now collect data, configure a device and control industrial devices.
CIPisanopenprotocolattheapplicationlayerfullymanagedbytheOpenDeviceNetVendorsAssociation
(ODVA,http://www.odva.org). Being that this is an open protocol there are many independent vendors offer-
ing a wide array of devices to the end user. CIP provides the ability to communicate utilizing both implicit
messaging (real-time I/O messaging), and explicit messaging (information/configuration messaging). For im-
plicit communications using a PLC, simply configure the PM assembly size into the I/O structure of the PLC
(See: CIP Implicit Assemblie Structures). The assembly structures can also be changed by the user.
Explicitcommunicationsrequirestheuseofspecificaddressinginformation.DeviceNetrequiresthatthe
node address be specified where EtherNet/IP requires just the Class, Instance and Attribute.
•NodeaddressorMACID(0-63,DeviceNetonly)
•ClassID(1to255)
•InstanceID(0to255)
•AttributeID(1to255)
EtherNet/IPandDeviceNetarebothbasedonCIPandusethesameaddressingscheme.Inthefollowing
menu pages notice the column header identified as CIP. There you will find the Class, Instance and Attri-
bute in hexadecimal, (decimal in parenthesis) which makes up the addressing for both protocols. The Watlow
implementation of CIP does not support connected explicit messages but fully supports unconnected explicit
messaging.
RockwellAutomation(RA)developedtheDF1serialprotocolwithintheframeworkofthePCCCapplica-
tion protocol. With the introduction of CIP, the PCCC protocol was encapsulated within it to enable continued
communication over Ethernet to the legacy RA programmable controllers, e.g., SLC, Micrologic and PLC-5
controllers equipped with Ethernet capabilities. The Watlow implementation of CIP also supports the PCCC
protocol.
EtherNet/IP (Industrial Protocol) is a network communication standard capable of handling large amounts
ofdataatspeedsof10Mbpsor100Mbps,andatupto1,500bytesperpacket.Itmakesuseofstandardoff-
the-shelfEthernetchipsetsandthecurrentlyinstalledphysicalmedia(hardwareconnections).DeviceNet
wasthefirstfieldbusofferingoftheODVAgroupandhasbeenaroundformanyyears.DeviceNetcancom-
municateat125,250and500kilobytespersecondwithamaximumlimitationof64nodes(0to63)onthe
network.
Note:
If the control is brought back to the factory defaults the user configured assemblies will be overwritten.
Note:
The maximum number of implicit input/output members using DeviceNet is 200. When using EtherNet/IP
themaximumis100.
CIP Implicit Assemblies
CommunicationsusingCIP(EtherNet/IPandDeviceNet)canbeaccomplishedwithanyPMIntegratedcon-
trolequippedwitheitherDeviceNetorEtherNet/IPcommunicationscards.Aswasalreadymentioned,read-
ing or writing when using CIP can be accomplished via explicit and or implicit communications. Explicit com-
munications are usually executed via a message instruction within the PLC but there are other ways to do
this as well outside of the focus of this document.
Implicit communications is also commonly referred to as polled communications. When using implicit com-
munications there is an I/O assembly that would be read or written to. The default assemblies and the as-
sembly size is embedded into the firmware of the PM control. Watlow refers to these assemblies as the T to
O (Target to Originator) and the O to T (Originator to Target) assemblies where the Target is always the EZ-
ZONE PM controller and the Originator is the PLC or master on the network. The size of the O to T assem-
blyisfixedat20(32-bit)memberswheretheTtoOassemblyconsistsof21(32-bit)members.Allassembly
members are user configurable with the exception of the first T to O member. The first member of the T to
OassemblyiscalledtheDeviceStatus,itisuniqueandcannotbechanged.Ifthemodulehasbeenproperly
configuredwhenviewingthis32-bitmemberinbinaryformatbits12and16shouldalwaysbesetto1where
alloftheotherbitsshouldbe0.The20membersthatfollowDeviceStatusareuserconfigurable.TheAp-
pendixofthisUser'sGuidecontainsthePMimplicitassemblies(SeeAppendix: CIP Implicit Assembly Struc-
tures).