How-to Video: PID Loop Control for A-B PLC Systems
New 32-Channel Digital Input with Positive Common Connections
Updated Modbus/TCP Integration Kit Now Available
Tech Tip: Offsite Testing Made Easy
One of the great things about using SNAP I/O with an Allen-Bradley PLC system is that you can offload some processor-intensive tasks to the remote I/O, thanks to distributed intelligence.
Functions like temperature conversion, analog scaling, ramping—and even PID loop control—are done in the I/O processor instead of the PLC.
If you need to do PID loop control, you'll want to watch our latest video. Engineer Alexi Beck Gray demonstrates how to set up PID loops in SNAP I/O, change the setpoint in RSLogix, and then tune your PID loop easily in the graphical tuning tool.
While you're there, take a look at the first three IO4AB videos, too. SNAP I/O makes it easier to expand your A-B PLC system and add process control features without increasing scan times or straining the system.
Watch the video now.
Schedule your own WebEx demo of SNAP I/O for A-B systems. Call 800-321-6786 or email firstname.lastname@example.org.
Here's a high-density digital (HDD) module with a negative input and positive common connections.
With an input range of -10 to -32 VDC, the new SNAP-IDC-32N is ideal for NPN or sinking-type inputs.
Providing 32 digital input channels in one compact SNAP module, the SNAP-IDC-32N is great for OEMs and others who have applications with high point counts. It also solves space problems if you need a lot of digital input channels on one SNAP PAC rack.
Like our other recently released HDD modules, the SNAP-IDC-32N works with SNAP PAC brains and R-series controllers. For easy field wiring, use the SNAP-IDC-HDB breakout rack and the SNAP-HD-BF6 header cable.
If you need the mirror-image cousin of the 32N—a high-density digital module with positive inputs and negative common connections—try the SNAP-IDC-32.
For specifications and wiring on all HDD modules, see form #1556, the SNAP High-Density Digital Modules Data Sheet.
Need to link to a Modbus system running over Ethernet?
Our updated Modbus/TCP Integration Kit for PAC Control gives you the tools to link Opto 22 SNAP PAC controllers to any Ethernet Modbus device and communicate using the Modbus/TCP protocol.
The kit includes:
- PAC Control master subroutines
- a sample Modbus/TCP slave strategy
- sample PAC Display master and slave projects
The integration kit has been substantially improved in version 8.2a. Data conversion is no longer needed and data accuracy is increased, since table and variable types match data types.
We've improved the user's guide as well, with new examples, a new troubleshooting chapter, information on upgrading from version 8.1, and better organization to help you find information quickly.
Download the updated Integration Kit now.
Ever worked on your PAC Control strategy or PAC Display HMI project someplace away from your controllers—maybe even at home on a weekend?
Here's a tip from Pre-sales Engineer Ben Orchard on the easiest way to do it—with PAC Terminal.
PAC Terminal is a small but mighty utility program that's installed with the PAC Project software suite or its components, such as PAC Control. PAC Terminal is easy to overlook, but it's a handy tool for working offsite, especially if you have multiple controllers to test.
Here's the key: Both PAC Control and PAC Display operate based on your controller's name, not its IP address.
That means you can change, run, and test your strategy or project without having the controller on hand. All you need is PAC Terminal and SNAP PAC Sim, free software that runs on a PC and simulates a SNAP PAC controller.
- Open PAC Terminal by choosing Start>Opto 22>PAC Project>Tools>PAC Terminal.
- For each controller you're testing, right-click its name in the list, choose Modify, and change its IP to 127.0.0.1 (the loopback address). Using the loopback address means your PC will look for a control engine internally rather than looking for an external controller. In PAC Terminal, it's easy to go down the list and change all the controllers you need to test.
- Make your changes in PAC Control or PAC Display. Choose the name of the controller you want to test as the active controller. In PAC Control, disable the I/O units to avoid errors (SNAP PAC Sim simulates the controller, but not I/O.)
- Launch SNAP PAC Sim. If Windows blocks some features of the program, unblock them. SNAP PAC Sim will simulate the controller.
- To test on a different controller, just choose its name to make it the active one.
NOTES on SNAP PAC Sim: You can only test one controller at a time (only one instance of the simulator can be open). SNAP PAC Sim will run for 12 hours before it expires. After that you have to start it again.
Questions? Comments? Contact Product Support.