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RSNetWorx for ControlNet

• What are scanner signatures?

  A scanner signature is an unique hexadecimal value that is assigned to scanner devices that originate scheduled connections; a copy of the scanner signature is held by the active keeper. This value is stored in the scanner and in the offline configuration, and is used to determine if the offline and online configurations are synchronized. When a scanner device with scheduled connections joins the network for the first time, it requests it's scanner signature from the active keeper. If the scanner signature matches the scanner signature obtained from the active keeper, then that device is allowed to open its scheduled connections. If the scanner signature does not match, then the device is not allowed to open its scheduled connections.

  Tip: To view the scanner signature for a keeper-capable device, select Network > Signature Status in RSNetWorx for ControlNet.

  Keep the following in mind:

  • When the scanner signature is the same in the scanner itself, the offline configuration file (*.xc), and the online active keeper, then connections are allowed to occur.
  • When the scanner signature is different in the scanner itself, the offline configuration file (*.xc), and the online active keeper, then connections are not allowed to occur. To resolve this condition, you must pick a starting point; that starting point is commonly the offline configuration file. If you download the offline configuration file to the online network, the scanner signatures in the online scanner and the online active keeper will be consistent. Then, you can click the Edits Enabled checkbox and begin working again.
  • When two out of three of scanner signatures agree, connections are not allowed to occur. To resolve this condition, you can assume that the non-matching scanner signature needs to be corrected. However, it could be that the two matching signatures are incorrect, while the remaining signature is correct. At this point, you must leverage your knowledge of your control system in determining a corrective action. Based on that expertise, you can then choose either to upload from the network or download to the network to rectify the non-matching scanner signatures.

• Why do I have to put all of my processors in Program mode to make a change?

  You do not necessarily have to put all of your processors into Program Mode when you make a change on ControlNet. When scheduling a network, RSNetWorx will typically offer you two choices when you save your configuration:

  • Optimize and re-write the schedule for all connections
  • Merge changes into existing schedule

  If you choose to Optimize and re-write the schedule for all connections, RSNetWorx will regenerate the schedule for all of the connections on your network. To use those new connections, all of the scanners (for example, PLC-5s, ControlLogix processors, etc.) will need to be placed into Program mode. In some cases, your only choice may be Optimize and re-write the schedule for all connections because RSNetWorx cannot leave existing connections in place and still make all of the changes that you have requested to the network.

  If you choose to Merge changes into existing schedule, RSNetWorx will leave as many connections untouched as possible. In this case, only those connections affected by the merge need to be updated; and only those scanners (PLC-5s, ControlLogix processors, etc.) that have been affected by those changes will need to be placed into Program mode.

  For example, imagine that you are using RSLogix 5000 and add a new 1756 I/O module under as existing 1756-CNB in the I/O tree. If you open RSNetWorx and the software determines that there is enough room in the current schedule to add the new module connection without needing to adjust any other connections and you select the Merge changes into existing schedule option when saving, only that one ControlLogix processor would have to be placed into Program mode.

• When I save changes, where does my ControlNet information go?

  The information in the ControlNet configuration is divided into several parts:

  • what the scanner needs (that is, a device with a scanlist. For example, a PLC-5C processor, the 1756- L1 processor, or a FlexLogix processor.)
  • what the keeper needs

  What the scanner needs

  • a configured connection (created in RSLogix 5000 for ControlLogix scanners, created in RSNetWorx for all other scanners).
  • the schedule for that connection (determined by RSNetWorx, and written to the scanner). The scanner then saves that information (if your in RSLogix 5000 and you save while online, the software will save this information to disk so that it can be downloaded in the future).

  After meeting these needs, the scanner signature is generated. The signature is used when the scanner wants to open up its I/O connections (for instance, when the scanner is powered up). The scanner checks in with the network keeper, asking for the signature that the keeper has recorded for 'this' scanner. If the signature that the scanner has for itself, and the signature that the keeper has for that scanner, are equal, then the scanner opens up its I/O connections.

  What the keeper needs

  The configuration software broadcasts the keeper information onto the network. The current active keeper will respond to the messages, but all keepers are supposed to listen and make the updates to their keeper information. The keeper information is:

  • the network parameter information (Unscheduled Max, Scheduled Max, the media configuration, and the Network Update Time [NUT])
  • the signatures for the scanners on the network

• My software is running slow over ControlNet and HMI performance is slow.

  Every ControlNet 1.5 system that has scheduled connections has an .XC file. This is the file generated by RSNetWorx for ControlNet. When you are viewing this .XC file, RSNetWorx for ControlNet displays in the upper left corner the number of Unscheduled Bytes Per Sec. As the number of Unscheduled Bytes Per Sec becomes smaller, performance of the software becomes slower. The same is true of the performance of HMI devices using unscheduled communication over ControlNet.

  For ControlLogix there is a tool that will help you determine if your system will be slow in responding. The tool is RSLinx. Go online with RSLinx and do a RSWho. Select the 1756-CNB or 1756-CNBR you are interested in, right click and select "Module Statistics". Then go to the "Connection Manager" tab. On the Connection Manager tab you will find the number of connections and the CPU Utilization number.

  Possible Solutions

  Perform one of the following:

  • Add another CNB/R and spread the load of connections.
  • Add another PLC-5C15 and spread the load of connections.
  • Break your network into multiple segments and message between segments.
  • Move your HMI to Ethernet

• When I load RSNetWorx for DeviceNet or ControlNet, I only get the splash screen without the software ever starting?

  To fix the problem, you will need to download RSLinx Hotfix Number A40145228 from Rockwell Software's Knowledgebase.

RSNetWorx for DeviceNet

• What is electronic keying and how does it apply to Allen-Bradley DeviceNet scanners?

  Every DeviceNet device has a set of attributes that collectively form its electronic identity. The electronic identity can be used to differentiate one device from another based on manufacturer, type of product, or revision level. Allen-Bradley DeviceNet scanners employ this electronic identity to form an "Electronic Key" that is used to verify that the devices connected to the network are the devices that were expected. Electronic keying allows you to configure your scanners to validate online device identities to a variable degree, providing reliable and trouble-free maintenance options for your network.

  In RSNetWorx for DeviceNet, the General tab displays the components of the electronic identity that can be used in keying. These components are as follows:

  • Vendor — defines the manufacturer of the product.
  • Device Type — distinguishes one type of product from another (for example, motor protector vs. limit switch).
  • Product Code — displays the number assigned by the manufacturer to distinguish one product from another.
  • Major revision — indicates the major revision of the product.
  • Minor revision — indicates the minor revision of the product.

  DeviceNet scanners must make I/O connections with devices before any I/O data is exchanged. Before the scanner attempts to make a connection, it checks that the identity of the online device matches the electronic key that it has saved for that node address. This electronic keying pattern is configured on a node-by-node basis. This feature then allows you to decide which criteria to use for each node on the network when verifying the online device.

  So how do you know what level of keying to use? This feature provides you with the power and flexibility to make that decision based on your knowledge and level of comfort with the products and their history of changes. But the consequences of your choice must always be considered. If the level of keying is too low (not enough criteria selected), the potential exists for you to install an incompatible device. If the level of keying is too high, you may be forced to reconfigure the system to accept a device that could have been replaced without any user intervention.

• How do I place my DeviceNet scanner in Run mode?
  When a DeviceNet scanner is in Idle mode, the scanner is gathering inputs, but it is not applying outputs to the other devices on your DeviceNet network. During normal operations, the DeviceNet scanner must be in Run mode. However, when you are downloading a new configuration to the scanner (or in some cases, other slave devices on your network), you should place the scanner in Idle mode.
• My drive comes up as an unrecognized device in the RSNetWorx for DeviceNet browse?

  Most drives you can upload the EDS file using the EDS Wizard (Ref KB A20913). Also the EDS files could be found on the WEB at: http://www.ab.com/networks/eds/.

• After changing parameters for a DeviceNet device node and power cycling, the device parameters return to their previous settings.

  ADR (Automatic Device Replacement) was enabled for this device in the scanner. After making device parameter changes, you must also re-save these changes in the ADR section of the scanner. Select ADR tab in the scanner properties, highlight device, select "Load Device Config" and select "Download to Scanner"

• After adding a node to the scan list, a 77 error is displayed on the Scanner.

  This error is generated when the specified IO size in the "Edit I/O parameters" (located in Scanlist tab) does not match the actual size that the device is reporting. This typically happens when the default size is selected in the scanner and an IO size parameter was changed for the device. For drives, these parameters can be called a DataLink, or an I/O Assembly. The best solution is to determine the correct I/O size from the device's manual.

• Does the 1769-SDN support explicit messaging?

  Yes, the 1769-SDN does support explicit messaging. The MicroLogix 1500 also has an enhanced message instruction that allows users to initiate explicit messages much easier than in the past. (CompactLogix will support explicit messaging in the future).

• Can I connect a computer to the MicroLogix or CompactLogix processors RS 232 port and configure DeviceNet devices ?

  Not at this time. When CompactLogix is enhanced to support backplane messaging this functionality is planned. We are not planning to support RS 232 port to 1769-SDN pass thru on the MicroLogix 1500 at this time.

• Does the 1769-SDN support ADR (automatic device replacement)?

  In the initial version ADR is not supported. We are planning for a firmware upgrade in the near future to include ADR support. Existing 1769-SDN's will be flash upgradeable and will support ADR at that time.

• When I load RSNetWorx for DeviceNet or ControlNet, I only get the splash screen without the software ever starting?

  To fix the problem, you will need to download RSLinx Hotfix Number A40145228 from Rockwell Software's website. To obtain the knowledge base, follow these steps:

  • Select 'Support' from the navigation bar, and choose 'MySupport' from the drop-down menu. This will take you to Rockwell Software's support page.
  • On the left-hand side of the page, click the "Online Tools" label under the Customer Support column to expand it. From the dropdown list, select knowledge base label. This will take you to the knowledge base page.
  • From the many options you will find on that page, you will be working with the options in the 'Product Type' group box.
  • Place your cursor in the textbox next to the "keyboard" label. In the textbox, enter '40145228.' Click 'Find.'

  You will see the Hotfix link message "A40145228:HOTFIX: RSLinx 2.41 - Failed to create empty document (after installing RSLinx 2.41 and RSNetWorx 4.x)" Click this message and follow the steps displayed with the message to download the Hotfix.

Maintenance and Diagnostics (MD)

• What is RSNetWorx MD?

  RSNetWorx MD is an optional component that provides pre-configured diagnostic and troubleshooting information for your DeviceNet and ControlNet networks (with EtherNet/IP coming soon!). With this diagnostic tool, you can detect problems with your network and devices immediately. You can even identify problems that cannot be discerned through visual inspection of modules and LEDs, or even through the status bits that are made available to your ladder logic by the scanner!

• Whenever I login into RSNetWorx (DeviceNet, ControlNet, EtherNet/IP), I get an error 'MD diagnostics activation was not found' in the message view of RSNetWorx's main screen.

  This message is displayed because you do not have activation for the RSNetWorx Maintenance and Diagnostics (MD) add-on. RSNetWorx MD:

  • allows you to resolve conditions that arise when initially commissioning a system, minimizing initial start-up times and costs.
  • helps you debug and correct network/device problems, thereby reducing network downtimes and related costs.
  • detects preventive maintenance needs within the devices on your network, thereby preventing system downtimes.

EDS

• From where can I download the EDS files?
  The EDS files can be downloaded from the web at: http://www.ab.com/networks/eds/.
• My device comes up as an unrecognized device in RSNetWorx following a browse (gray colored question mark appears on my device).
  This error occurs when your device doesn't have an associated EDS file. The EDS files can be downloaded from the web at: http://www.ab.com/networks/eds/.
• When I install RSLinx 2.41 and RSNetWorx 4.01 or later, I get an error "Failed to create empty document."
  This error may occur due to the following reasons:

  • A corrupt Harmony Cache file
  • A failed install of RSLinx
  • Insufficient permissions

  To fix the problem, you must download the Hotfix Number A40145228 from Rockwell Software Website. Follow these steps, to obtain it:

  1. Select 'Support' from the navigation bar, and choose 'MySupport' from the drop-down menu. This will take you to Rockwell Software's support page.
  2. On the left-hand side of the page, click the "knowledgebase" label (second from top) under the Technical Support column. This will take you to Rockwell Software's knowledge base page. From the many options you will find on that page, you will be working with the options in the 'Product Type' group box.
  3. Place your cursor in the textbox next to the 'keyword' label.
  4. In the textbox, enter '40145228.'
  5. Click 'Find.'
  6. You will see the Hotfix link message "A40145228: HOTFIX: RSLinx 2.41 - Failed to create empty document (after installing RSLinx 2.41 AND RSNetWorx 4.x)" Click this message and follow the steps displayed with the message to download the Hotfix.

• Where can I find the EDS file for my DeviceLogix devices?
  The EDS files for DeviceLogix devices are contained in the RSNetWorx's installation CD in the "Additional EDS Files" folder, or you can download them from the web at http://www.ab.com/networks/eds/.