Allen Bradley Technical Support
In over 15 years of experience with PLC systems, Qualitrol International has supported thousands of PLC installations. We have amassed a wealth if technical information to help you with system configuration and troubleshooting problems.
With our combination of Allen-Bradley repair services and remanufactured parts, Qualitrol International will keep your Allen-Bradley PLC system running for years to come.
We have created a list of Frequently Asked Questions (FAQ) regarding your Allen-Bradley PLC systems.
If you need additional technical assistance, you can call our Engineers at 1-800-784-9385, email us your technical support question at firstname.lastname@example.org, or click here to chat live with one of our engineers.
- Allen-Bradley Programming Software
What software do I need to program the different Allen-Bradley PLC platforms?
RSLogix 5 – PLC 5
RSLogix 500 – MicroLogix (Bul. 1764), SLC500 (Bul. 1747)
RSLogix 5000 – FlexLogix, CompactLogix, ControlLogix
What are the major differences between RSLogix platforms?
RSLogix 5 and 500 are conventional ladder logic program environments. They support the usual relay logic functions as well as higher level math, bit, timer/counter, compare, move, etc. RSLogix 5000 supports these standard ladder logic functions as well as function block, sequential function chart, and structured text (note – not all versions of RSLogix 5000 support all languages). RSLogix 5 and 500 are good for machine logic control. RSLogix 5000 is good for coordinated drive control, motion control, and process control.
- How do I know what the latest version of Rockwell software is?
With Allen-Bradley ControlLogix, CompactLogix, and FlexLogix does it matter if my firmware version and software versions are different?
In the Logix family (not including MicroLogix), programming software and controller firmware must be in “lockstep”. What this means is the major revision of the software and controller firmware must be the same. For example, if you have a ControlLogix CPU that has been flashed to version 18 firmware, your RSLogix 5000 software must be version 18 as well.
How do I download the latest software and controller firmware?
You must have a technical support contract (called Tech Connect) in order to have access to the restricted websites to download controller firmware and programming software. Access to these restricted sites can be made from http://www.rockwellautomation.com/support/americas/index_en.html.
What is Rockwell RSLinx and why do I need it?
RSLinx is an OPC server used by Allen-Bradley to connect their various PLC programming software products (see above) to their respective PLC hardware platforms. With few exceptions, RSLinx is necessary to set up communications between the programmer and the PLC. There are many different versions. In many cases, the freeware version, RSLinx Lite, can be used if only required for programmer to PLC connections. Linx Lite has no OPC tags and cannot be used to set up connections to a generic OPC client. But, in many cases, it will work for basic programmer connectivity.
What are EDS files and why is it important that I have the latest ones?
An EDS file is an Electronic Data Sheet. EDS files are used by RSLinx to identify the hardware to which it is connected and with which it is communicating. For RSLinx to access all the functionality of the communication port to which it is connected, the EDS file must be correct for the current hardware revision of the device to which you want to connect. Usually, the latest EDS file will work with the current hardware firmware and earlier versions. EDS files can be downloaded at http://www.rockwellautomation.com/resources/eds/. A Tech Connect contract is not required to download EDS files. If you don’t have the correct EDS file for the device with which you are attempting to communicate (usually when you click on RSWho from within RSLinx), you will see yellow question marks for the devices indicating that RSLinx recognizes that there are devices there but it has incomplete or out of date information in order to correctly communicate with the device. When your EDS files properly match the device to which you are connected, an icon will display that matches the device. Once you have downloaded the EDS files, use the EDS Hardware Installation Tool that comes with RSLinx.
- Allen-Bradley Networks
What are the different communication networks that Allen-Bradley uses?
Allen-Bradley primarily uses three industrial networks – ControlNet, DeviceNet, and Ethernet/IP.
Allen-Bradley still supports remote I/O (RIO), Data Highway, and Data Highway Plus (DH+). These are connected over the traditional AB “blue hose” (Belden 9463 or equivalent). These networks are not recommended for new applications and Allen-Bradley is actively trying to move users to ControlNet, DeviceNet, or Ethernet/IP.
What is each Allen-Bradley Network primarily used for, and what are their advantages and disadvantages?
ControlNet – as the name implies, this is used primarily in control applications where network speed and determinism are very important. ControlNet operates at 5 mbaud and network update times (NUT) are fixed. RSNetworx for ControlNet is required to setup and schedule the network. The physical medium is either quad shield RG-6 coax (Allen-Bradley 1786-RG6 or Belden 3092A) or fiber optic cable. In a copper configuration, the coax functions as a trunk line and network taps are required for each node on the network. Allen-Bradley supports a wide variety of devices on ControlNet including I/O, drives, and operator interface products.
DeviceNet – as the name implies, this network was originally intended for communication to device-level hardware such as photo-eyes, operator devices, switches, and other simple industrial sensors. DeviceNet operates at different baud rates depending upon the network length and number of devices on the network. The maximum rate is 500 K. There are several different types of cables available such as “thick” and “thin” cable. Some Belden DeviceNet cables are:
7897A – 600V class 1 thick, 15 & 18 AWG
3082A – 300V class 2 thick, 15 & 18 AWG
3084A – 300V class 2 thin, 22 & 24 AWG
DeviceNet Communications Rate Table
Maximum Distance 7897A 7896A 7900A 3082A 3082F 1345F 3083A Ft. m Ft. m Ft. m Ft. m Ft. m Ft. m Ft. m 125 Kbps 1640 500 1378 420 328 100 1640 500 1640 500 1640 500 1640 500 250 Kbps 820 250 656 200 328 100 820 250 820 250 820 250 820 250 500 Kbps 328 100 328 100 328 100 328 100 328 100 328 100 328 100 Communications
Maximum Distance 3084A 3084F 1346F 3085A 7895A 3082K Ft. m Ft. m Ft. m Ft. m Ft. m Ft. m 125 Kbps 328 100 328 100 328 100 328 100 984 300 1378 420 250 Kbps 328 100 328 100 328 100 328 100 820 250 656 200 500 Kbps 328 100 328 100 328 100 328 100 328 100 246 75
DeviceNet has the advantage that both 24VDC power and communications are combined in one cable so for instance a photo electric sensor can simply clamp on to a main trunk line and no further connections are necessary as both power and communications are provided in one cable. A wide variety of network connection and termination hardware is available from several different manufacturers.
Ethernet/IP – Allen-Bradley is moving more and more of their hardware platforms to this network. They do typical HMI communications to controllers which are not time critical. They also do control over Ethernet/IP and guarantee deterministic operation when the network is properly configured. When used in control applications, a managed Ethernet switch is required.
- Allen-Bradley I/O Platforms
What are the different Allen-Bradley I/O platforms?
The most common chassis-based I/O are ControlLogix (1756), SLC (1746), MicroLogix (1762), CompactLogix (1769), PLC-5 (1771). These I/O platforms may be controlled directly by a CPU mounted in the rack with the I/O or they may be located remotely from the CPU rack and controlled over one of several networks such as ControlNet, DeviceNet, Remote I/O, or Ethernet/IP.
The most common distributed I/O platforms are Flex I/O (1794), and Point I/O (1734). These remote I/O modules can be controlled over the same networks as for the chassis-based I/O with the appropriate network adapter module. There are additional I/O types that are less prevalent but that are good choices for certain applications. They include:
CompactBlock (1790) which supports DeviceNet and Profibus networks. A wide variety of digital and analog modules are available. This is Allen-Bradley’s most “open” offering and is designed to be used with anyone’s Profibus or DeviceNet network scanners.
Block I/O (1791) which supports Allen-Bradley universal Remote I/O. As the name implies, this is a block or “brick” form factor that combines various digital inputs, digital outputs, analog inputs, and analog outputs on a single block. It is not expandable although several block I/O modules may be part of a single network.
Flex EX I/O (1797) which is a variant of 1794 Flex I/O that includes an intrinsically safe (IS) barrier for use in Class I, II, and III, Division 1 environments.
- Allen-Bradley Operator Interface Products
What are the different types of operator interface products that Allen-Bradley offers, what networks do they support, and what is the best network to use?
Allen-Bradley is best known for their PanelView products. The traditional PanelView terminal is available in monochrome and color versions from 3” to 10”. Most support a broad variety of Allen-Bradley network protocols including Ethernet/IP, ControlNet, DeviceNet, Remote I/O, serial (DF1 and DH-485), and DH+. Most have touch screens and also may have keypads. The traditional PanelView has a proprietary operating system. These units are programmed using Allen-Bradley PanelBuilder32 software.
A newer PanelView platform is the PanelView Plus. This is based on the Windows CE OS. The PanelView Plus family of terminals are available from 5” to 15” units. They support Ethernet and RS232 communications as standard and with the addition of a network module, they can sit on ControlNet, DeviceNet, and Remote I/O. The standard PanelView Plus terminal does not allow access to the Windows CE desktop. If standard Windows CE functionality is necessary, the PanelView Plus CE product must be specified. The PanelView Plus is programmed with Factory Talk View Machine Edition software.
Which unit is better, the standard PanelView or PanelView Plus?
In almost every situation, the PanelView Plus is the better choice. In most cases it is priced below the standard PanelView for the same size screen. It comes with Ethernet communications as standard which is an expensive option on the standard PanelView. The graphics on the PanelView Plus are much richer and allow the configuration of applications that rival full blown SCADA systems in terms of the GUI (graphical user interface), and well as some other features such as support for recipes, trending, and data logging.
Where a PanelView Plus becomes limited is because of its lack of a hard drive which restricts how deep trends and data logs can be. However, for most machine-level operator interface applications, not having a hard drive is a good thing and SCADA systems that employ even “hardened” industrial computers are better kept off the factory floor and in cooler, cleaner, less hostile environments that a PanelView or PanelView Plus work very well in.
What is the best network to use on a PanelView or PanelView Plus?
For a PanelView it depends on what network interfaces you have on your PLC. A standard PanelView must be ordered with the network interface you want – none comes standard. A PanelView Plus comes standard with Ethernet and it is hard to imagine why you would employ one of their other networks which are expensive options. Ethernet is fast, open, and all programming computers have an Ethernet port. Ethernet is becoming standard on most PLC systems today at least for operator interface support if not for I/O control as well.
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