New Leakage-Tolerant High-Density Digital Input
PAC Display Tips and Tricks Video
Hot Tips from PSG: PAC Control Hints
Have You Tried Background Downloading?
New Leakage-Tolerant High-Density Digital Input
Our new SNAP-IDC-HT-16 leakage-tolerant digital input module was developed for use with inductive proximity switches and sensors that have a high leakage current.
The new module offers channel-to-channel isolation for 16 points and senses on/off status for loads of 15–28 VDC/VAC. Like other high-density digital modules, it also features automatic counting and latching.
The SNAP-IAC-HT-16 works with SNAP PAC rack-mounted controllers and SNAP PAC brains. The module mounts on any SNAP PAC rack along with other analog, digital, and serial I/O modules.
For specifications and wiring, see form #1556, the SNAP High-Density Digital Modules Data Sheet.
PAC Display Tips and Tricks Video
Before Pre-Sales Engineer Ben Orchard came to work at Opto 22, he used PAC Display (and its predecessors, ioDisplay and OptoDisplay) to build complex HMIs in Victoria, Australia.
Over a period of 18 years, Ben's HMI for a hospital grew from two windows to over 1000. He learned a lot in those 18 years, and we captured some of what he learned in this new video: PAC Display Tips and Tricks.
From setting up a project template to including extra data your technicians will love you for, Ben shows you ways to make your job easier.
Watch the video now.
Hot Tips from PSG: PAC Control Hints
From our Product Support Engineers, here are a couple of helpful hints for using PAC Control, the control development software used with all SNAP PAC controllers.
Delay Tactics
A simple delay is a powerful tool. If a condition block continually loops waiting for the condition to be true, it unnecessarily uses the chart's "time slice" by constantly checking the same condition.
Instead, build in a slight delay using the command Delay (mSec) with a value of at least 1. This command causes the chart to wait one millisecond before checking the condition again.
To learn about time slices and more ways to make your strategy efficient, see the section "Optimizing Throughput" in the PAC Control User's Guide (form #1700).
Troubleshooting Hint
Use the Comment (Block) command to "comment out" one or all instructions (commands) in a block. Any command that is commented out is skipped when the strategy runs. If you're having problems, comment out part of the block to pinpoint the problem.
Remember you can use the equivalent command (/* and */) in OptoScript, where it can sometimes be harder to see errors. In an earlier OptoNews we showed you how to use comments in an OptoScript block to find the missing piece of an if/then/else/endif statement. You can also comment out any section of an OptoScript block to pinpoint other errors.
Questions? Comments? Contact Product Support.
Have You Tried Background Downloading?
In the real world, stopping a running strategy to load or test a new one may cause unacceptable downtime.
Background downloading in PAC Control minimizes process downtime by letting you load an alternate strategy while the active strategy continues to run.
With background downloading, you can:
- Start running a new or updated strategy much faster. For larger strategies, downtime is dramatically reduced.
- Test a new or updated strategy but still keep the original strategy in the controller. You can quickly switch back manually using PAC Control Debug mode. Or, if the original is still burned to flash, you can switch back by cycling power.
- Download a diagnostic strategy as well as the one driving your process. Switch between them as required to easily test all the points and functions.
To handle background downloading, PAC Control divides the control engine's memory in half—half for the running strategy and half for the alternate strategy. Half the memory should be sufficient for all but the largest strategies. Since flash memory is also split in half, both strategies can be saved to flash.
Background downloading isn't automatic; you need to turn it on in PAC Manager and PAC Control.
Full details are in the PAC Control User's Guide. Just check the index for "background downloading."