Cip - Communications Capabilities - Watlow PM LEGACY PM3 User Manual

CIP - Communications Capabilities

With the introduction of the Common Industrial Protocol (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 offering 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 implicit communications using a PLC,
simply configure the PM assembly size into the I/O structure of the PLC (See: CIP Implicit Assembly
Structures). The assembly structures can also be changed by the user. Explicit communications re-
quires the use of specific addressing information. DeviceNet requires that the node address be speci-
fied 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 fol-
lowing menu pages notice the column header identified as CIP. There you will find the Class, Instance
and Attribute in hexadecimal, (decimal in parenthesis) which makes up the addressing for both proto-
cols. The Watlow implementation of CIP does not support connected explicit messages but fully sup-
ports unconnected explicit messaging.
Rockwell Automation (RA) developed the DF1 serial protocol within the framework of the PCCC appli-
cation 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 communicate 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 (See Appendix: CIP Implicit Assembly Struc-
tures) the user configured assemblies will be overwritten.
Note:
The maximum number of implicit input/output members using DeviceNet is 200. When using Ether-
Net/IP the maximum is 100.
Wa tl ow P M LE GACY™ Lim it C o nt ro l le r 9 6
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C hapter 8 Features