Generac Power Systems H-100 technical manual Ilc, ‹ Local Trending, ‹ Genlink Local Trending Setup

General Information

H-100 Control Panel Technical Manual

‹LOCAL TRENDING

Local trending is done inside the controller where up to 1000 samples can be stored in memory. GenLink provides an interface to select the analog channels to be trended, the rate to be sampled at, and optional triggers to be used to specify when to sample. Up to 6 analog channels can be sampled. However, the 1000 samples are divided by the number of channels. For example, there will be 1000 samples of 1 channel or only 166 samples of each of 6 channels. The analog samples can be sampled at one of three basic polling rates: Low Speed, Mid Speed, and High Speed. For the Low Speed and Mid Speed modes, there are also several settings that can be used to determine when to sample. GenLink can save the data to a file and/or display it as a snap-shot graph. The file is MS Excel compatible ( CSV format ).

‹GENLINK LOCAL TRENDING SETUP

When setting up the local trending, verify that the “Armed” box is unchecked and press “Apply”. To change the settings with the trending armed may result in corrupted data. Select a rate at which to take samples.

•Low Speed rate samples the processed analog channel values at a rate that is able to be set in increments of 0.1 seconds.

•Mid Speed rate is about 2 milliseconds which captures the new analog channel value as soon as it is processed by the measurement and alarm modules.

•High Speed rate is 0.4 milliseconds and is reserved for the raw AC wave forms of generator voltage and current.

There are 6 pull-down boxes that allow the selection of up to 6 analog channels. All channel pull-down boxes after the first pull-down box with NULL CHANNEL selected are ignored. If High Speed is selected, the pull-down boxes are not used. Instead, there are 6 check boxes that can be used to select which voltage and current lines are to be trended.

The “Capture When” pull-down box allows the trend- ing to be limited to the engine running or engine being stopped. If the “Stop at End of Buffer” box is selected, then the trending will start when the “Capture When” condition is true and stop when the 1000 samples have been taken.

Any digital or analog channel can be used as an event trigger. The event trigger needs to be set up in that channel's setup screen. Checking the “Capture Only When Trigger is True” box will cause the samples to only be taken while the event trigger is true. Checking the “Capture on Shutdown Alarm” will cause the sam- ples to start upon the setting of a shutdown alarm. The event trigger can be used to start sampling, stop sampling, or center the sampling by selecting the appropriate radio button:

No Trigger

The event trigger is ignored and samples are continu- ally being placed into the buffer.

Pre-Trigger

Samples are continually being placed into the buffer until the event trigger becomes true. Then no more samples are placed into the buffer.

Post-Trigger

No samples are placed into the buffer until the event trigger becomes true. Then samples are placed in the buffer until it is full.

Pre- and Post-Trigger

Samples are continually being placed in the buffer until the event trigger becomes true. This point is considered ½ of the buffer. Samples continue to be placed into the buffer until it is full.

Pressing the “View” button will show a graph of the samples in the buffer at the time the button is pressed. The graph has a “Save” button that allows the user to save the data out to a file in a MS Excel compatible ( CSV ) format.

THE ILC

The built-in ILC uses simple combinatorial logic to generate digital outputs and limited generator con- trol. The ILC uses ladder logic for programming, and a separate offline programming tool is avail- able to generate the ILC programs. These are then downloaded via GenLink and are started or stopped by means of a checkbox on the GenLink ILC page. Once downloaded and started, they will remain active unless they are stopped via GenLink, even if power is cycled.

The I/O scan time of the ILC is about 100 ms worst case. This means that all inputs and outputs are scanned within 100 ms. Also, the ILC processes one rung every 5 ms, so 5 rungs will take 25 ms. However, this is in parallel with the I/O scan and not added to it.

The offline tool uses graphic symbols to design the “rungs” of the ladder logic. The rungs are simple and can only have 2 combinatorial elements in them, but by the use of “soft contacts” the output of one rung can be fed into the input of another to provide more combinations. As well as the logical combinations, there are also analog comparisons, counters and tim- ers available for use in the rungs. As an example this allows the following type of logic to be built:

IF (in automatic) AND (engine running) AND (air temperature >25 deg) FOR (20 seconds) THEN OPERATE (output 7).

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