admin, Author at Building Systems LLC

August 4, 2020

BACnet ASOS Report- July 2020

March ASOS summery below.

Total Hosts with 47808 Exposed – 22,908
Total BACnet Hosts – 12,604
Total Unknown / Suspected BACnet- 1,084
Total Unknown – 10,304
Total Number of Vendors – 122

August 4, 2020August 4, 2020

BACnet ASOS Report- June 2020

June ASOS summery below.

Total Hosts with 47808 Exposed – 22,550
Total BACnet Hosts – 12,629
Total Unknown / Suspected BACnet- 1,144
Total Unknown – 9,921
Total Number of Vendors – 120

April 24, 2020

BACnet ASOS Report- March 2020

March ASOS summery below.

Total Hosts with 47808 Exposed – 19,979
Total BACnet Hosts – 13,044
Total Unknown / Suspected BACnet- 1,338
Total Unknown – 6,935
Total Number of Vendors – 119

April 24, 2020

BACnet ASOS Report- April 2020

April ASOS summery below.

Total Hosts with 47808 Exposed – 22,494
Total BACnet Hosts – 13,207
Total Unknown / Suspected BACnet- 1,336
Total Unknown – 9,287
Total Number of Vendors – 124

April 10, 2020April 12, 2020

Using Trend IQLvav Controllers in Niagara

Trend Lon controllers typically installed in “Trend” mode which self-install on a Lonworks system and use standard Lan / outstation numbers as any of the other Trend modules. Devices are typically software addressed with an LCI and IQLtool built into SET. This works well but requires a Trend 3Xtend or the newer Xtend module to route Trend Lon devices on to Ethernet or current loop networks.

Trend’s default addressing scheme on Lon translates as follows:

Domain Table = 1
Domain Length = 1 byte & ID 255 or FF hex
Subnet = 255 – Trend Lan number (1,4-119 are valid Lan numbers)
Node = Trend outstation number (1,4-119 are valid outstation numbers)
Message Code = 64
Domain Wide = domain wide
Router Buffer Size = 146 bytes

If the IQL has the above settings, it will still communicate with the Xtend and the standard tools. This is the case, even if its Lon managed.

Consequences of switching to Lon managed

The IQLvav datasheet has all the points listed that convert directly to SNVTs. The main points that will no long be available are:

Airflow setpoints including K factor
Velocity pressure input and the ability to zero it
Damper, hot water positions and electric heat outputs
Alarm input
Damper override settings

The airflow setpoint is also a temp SNVT which cannot be directly converted within the point setup in Niagara. Connect a multiple block and multiply this reading by 2.119 to convert to cfm.

Pulling the IQLvav into Niagara

The easiest way to bring these in first figure out how the controllers are addressed and setting the Jace Lon domain length and ID to match the existing controllers. In most cases it will be the defaults from above. To verify this, right click on the Lon network and choose Lon Utilities view, then pick identify and hit the service pin on one of the modules.

In this example the IQLvavs subnet is 230 which is Trend Lan 25 (255 – 25 = 230) and Outstation 30. We can see the domain length is 1, domain ID is 255 which is what we need to set the Jace for in order to discover the rest of the devices. Right click on the Lon network, open its property sheet and expand the Lon Netmgmt. Set the domain length and ID to match what was discovered with the service pin.

Niagara Lon network setup matching Trends default settings

After saving this, you should be able to open the Lon network and discover the IQLvavs.

At this point you can drag in the discovered devices. In order to get all the point names, you need either the devices XIF file or already converted an XIF into the LMNL format that Niagara uses. XIF files can be converted under Tools – Lon XML Tool. Links to both formats below.

When you drag the device down into the database, assign the attached LMNL file in the add window.

Adding an LMNL file to a newly discovered device

You can now import points, readdress and commission the devices as any other Lon device. Keep in mind if you change the domain length or ID from the default, they will no longer communicate with the Extend, LCI, SET, etc. IQLtool will not be able to address IQLs that have been Lon managed unless they are switched back to their default mode.

Returning a Lon managed IQLvav back to its default Trend mode

If you have changed from Trend’s default addressing and need to adjust the settings that are no longer available, you will need to restore them in order to connect with an LCI & SET. Change the domain length back to 1 and the domain ID back to FF if these have been changed. Upload the device by right clicking on the device Actions – Upload. Then select the nc Manager view. In that window change the nciNetConfig to cfgNul. Then download the change by right clicking on the device Actions – Download.

At this point the IQL will reset and will communicate with the standard Trend tools. Note that the address will default to Lan 1 Outstation 1.

Additional notes

Never change nviSecurityCode under any circumstance. This is a copy protection scheme that is used with nvoGenerator. If the security code is changed from its factory value the controller will cease to process it program. It will still communicate, but nothing will function. These controllers are no longer supported, so don’t expect factory support to recover from this.

March 26, 2020April 24, 2020

BACnet ASOS Report- February 2020

February ASOS summery below.

Total Hosts with 47808 Exposed – 19,981
Total BACnet Hosts – 12,966
Total Unknown / Suspected BACnet- 1,320
Total Unknown – 7,015
Total Number of Vendors – 126

February 2, 2020August 4, 2020

Low cost Ebay 4-20ma / 0-12vdc signal generator

I recently needed a handheld signal generator to supply 0-10vdc signals to setup some analog controllers. In the past I have used everything from a 9v battery to the Kele ASG. In this case I borrowed an ASG and got the job done but was not terribly impressed with it. It only has a LED bar graph to show the current output and its limited to 1vdc or 2ma steps. A bit of looking around on Ebay, I found a large selection of low-cost signal generators marketed for PLC/HVAC controls market. This is a quick look at one of them, the WZ Signal CVS III. This can be found on Ebay for between $25-30 delivered.

What I don’t like about the Kele ASG:

High cost ~$100
Only course adjustment of generated signals
Uses a 1/8” headphone connector for leads / pain to field replace
Bar graph display does the job, for the cost would expect better
20ma/10vdc max output doesn’t allow testing outside normal ranges
4 button interface not user friendly

For an instrument I rarely need its likely lost or the battery leaks destroying it before I need it again. For the cost, would expect better control of the output signals and something simple enough to pick up and use without hunting for manuals. Using the 1/8^”phono jack for the test leads means losing the leads or developing a broken conductor at the jack requires a soldering iron or new set of leads.

What I like about the CVS III:

Low cost – $25-30 delivered
USB micro rechargeable battery
Standard terminal block interface to test leads / easy to replace
Fine adjustment of output signals
Digital readout display
24vdc output to power low current devices

Being impressed with such a low-cost generator, I did some tests to see how it preforms. The unit can supply a 20ma signal for little over 3 hours on a full charge. Under ~13ma signal just over 4 hours. Didn’t bother testing voltage signals but it would be much longer. Powering the display and boost converter would steal more power than the voltage output.

Accuracy of the output I checked against my Keithley 2000 bench VOM and it was more than enough for anything I would require.

While testing how long the battery would last, I did notice the unit has no real low battery protection. The unit will disable the output signal when battery voltage falls below 2.88v, but the 24v output and display continue. Being the case the, there is still load on the battery and its voltage continues to drop. At ~2.7 Vbatt, the unit starts rebooting and will continue to load the battery until switched off. This of course will damage the internal lithium battery given it’s a bare non-protected cell. The unit does appear to have a charge controller so overcharging shouldn’t be an issue.

A look under the hood, it’s a well constructed unit. As typical with such low-cost devices from the usual parts of the world, all the IC part numbers have been sanded off. Being the case, I’m not going to bother diving into the design. From a quick glance it’s what one would expect. Boost converter, processor driving the output and display and charge IC, nothing special. The I/O terminals do appear to have at least diodes protecting them. All through hole parts have been hand soldered. I would note that the battery connections are very close together. Seems silly given they are hand soldered and space isn’t a problem. Also near the battery pack are the through hole headers to the display. If the battery pack is misaligned these could puncture the cell.

All in all, its hard to complain about such a low-cost item. The lack of low battery protection is a miss. That said, it’s easy enough to either replace the cell or just purchase another. No directions are included with the unit. The Ebay listing shows the wiring connections and terminal labels are far from clear. Below is how the unit should be connected in various cases and some of my test results.