dh+远程通讯.pdf

G16913 - ControlLogix Gateway: DH+ Communications Last Modified: 06/28/2006 Previously Released as #10801 ControlLogix Gateway Communication Between DH+ Networks Data Highway Plus (DH+ or PCL (Peer Communications Link)) was released by Rockwell Automation (Allen-Bradley) in 1986. DH+ is an old architecture relative to Ethernet and ControlNet used with the ControlLogix Gateway. The DH+ protocol/architecture is not capable of containing all the of information necessary to navigate the ControlLogix Gateway alone, this is the reason for the 1756-GTWY software. RSLinx Classic v2.0 or higher (or the 1756-GTWY configuration software) provides additional routing table information to the DHRIO module describing the networks available so a path can be established for DH+ messages. What is Required by DH+ Devices to Utilize the ControlLogix Gateway As a general rule, devices that communicate through the ControlLogix Gateway from DH+ must have the ability to Remotely message and make use of Link IDs. When determining if your device will communicate through the ControlLogix Gateway look at the other product being used. Does its DH+ port have a parameter or dip switch available to configure a Link ID for that channel? Does the product have the capability with its communications or in its messaging command to Remotely message? Look for the key words Remote and Link to determine if your product can make use of the ControlLogix Gateway. The fundamental purpose of a Link ID is to number each Data Highway Plus when multiple DH+ networks exist. The Link ID provides a way for the ControlLogix Gateway to determine what DH+ network a message should go to. Ideally, all devices on a DH+ network should have matching Link ID parameters. When a device is not capable of specifying its Link ID, by default it is 0 or undefined (that portion of the DH+ data packet is not filled out). A device without a Link ID can exist on a network with devices that have a Link ID parameter. Devices without a Link ID parameter will not be able to initiate a message through the ControlLogix Gateway and only have the capability to message with the devices on that local network. Note: SLC-5/04 processors PassThru Link ID on Channel 1 must match the Link ID value set on the corresponding DHRIO module that is is connected to. Remote messaging capability provides the ability for a device to message from the Local DH+ network, through a Bridge or Gateway, to another Remote network of some type. The main General Information General Category: s Programmable Controllers Programmable Controllers - I/O Communications and Network Products Product(s): SLC500 (1747); ControlLogix (1756); Interface/Comm (1770); PLC5; RSLinx Catalog #:1756DHRIO; 1756GTWY Series / Revision: Subject (Keyphrases):communication, dh+/dh/dh485, processorsSummary of Technote Information:Page 1 of 21General Information Technote: ControlLogix Gateway: DH+ Communications9/14/2006 between a Local message and a Remote message is the use of an additional parameter referring to a Local Bridge node address which is used to access the remote network. A remote message can also require the Link ID of the remote network and, in some cases, specify a network type like Data Highway (not DH II or Other). Some older revisions of processor firmware can have problems remotely messaging with the newer technology. Update PLC-5/11, -5/20, -5/4x, -5/60 and -5/8x Series A, B, and C to revision M firmware or later; update SLC-5/04 to OS401 FRN 5 or later. DF1 interfaces like the 1770-KF3, 1747-KE, 1770-KF2 and 1785-KE do not support remote addressing (the DF1 protocol, explained in Publication 1770-6.5.16, doesn't support remote Link IDs). These devices can not communicate through the ControlLogix Gateway to other remote networks. Remember: the key words in the criteria for using the DHRIO mentioned are Remote and Link. You will see neither DH+ to -DF1 device, 1785-KE or KF2, can use a remote link ID. How to Navigate Multiple Data Highway Plus with the ControlLogix Gateway Now that we understand the criteria required for a device to utilize the ControlLogix Gateway, we'll discusses how to configure the ControlLogix Gateway to join multiple DH+. The core example for this document consists of three different links, one DH+ is common to two ControlLogix Chassis, the Initiator is connected to a DH+ associated with the first ControlLogix Chassis (designated by the RSLinx terminal), and the target is connected to a DH+ associated with the second ControlLogix Chassis (designated by the PLC). The Initiator (on Link 51) will communicate through the first ControlLogix Chassis, onto the shared DH+ (Link 12) into the second ControlLogix Chassis, and access the target on the third network (Link 13) . Page 2 of 21General Information Technote: ControlLogix Gateway: DH+ Communications9/14/2。