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JamesL92878,
It sounds like you have an NDM from your comments. I haven't touched/worked with one for many years.

If memory serves, you have to use "Auxillary Access" in the Configuration Tools menu to connect to one and then use HVAC-Pro to access the N2 devices. The PC/Laptop has to have a similar modem to the one connected to the NDM (same speed and maybe same Mfgr/model on both ends).

A photo would be helpful.

Originally Posted by berg2666

And your automated logic front end is going to be able to program JCI N2 devices? I am very interested in how you will do that I may be interested in using the product...

Automated Logic cannot program the N2 devices but it does make a fine head end. They have their own integration to N2 Open devices. When the job involvess DX-9100 or VMA devices many of their dealers use our BACnet-N2 Router.

Originally Posted by steves4

Or, possibly just update the drivers on XP. You'll need to look into modem compatibility with the Metasys dialer and software. That is a device I have never worked with.

Ok thank you. This has been very helpful.

Originally Posted by JamesL92878

Now is it possible to just replace both modems at local office and at remote site to fix the problem?

Or, possibly just update the drivers on XP. You'll need to look into modem compatibility with the Metasys dialer and software. That is a device I have never worked with.

Originally Posted by JamesL92878

That could be possible. The guy who used to have the computer is no longer here. The computer is currently XP and as far as I know it has always been XP

Now is it possible to just replace both modems at local office and at remote site to fix the problem?

Originally Posted by steves4

Did you possibly upgrade your Windows PC? There could be a driver problem with the modem.

That could be possible. The guy who used to have the computer is no longer here. The computer is currently XP and as far as I know it has always been XP

Originally Posted by JamesL92878

Hey steve thanks. The modem is connected to a dialer and the dialer connects into the UNT controller. The weird this is that if I plug into the N2 on the dialer I can get into the controls on site. Plus we only have 2 sites that are like this as far as having to use external modem. Both sites stopped working around the same time.

Did you possibly upgrade your Windows PC? There could be a driver problem with the modem.

Hey steve thanks. The modem is connected to a dialer and the dialer connects into the UNT controller. The weird this is that if I plug into the N2 on the dialer I can get into the controls on site. Plus we only have 2 sites that are like this as far as having to use external modem. Both sites stopped working around the same time.

Originally Posted by JamesL92878

I have some sites that have N2 Devices. They used to have external modems, were using and aux access program and using external modem. They external modem will dial and connect to modem at site. But when I try to connect to site with hvac pro the site doesnt show any devices. It used to work for years and it just stop working. Any suggestions why?

Based on this information it sounds like the modems and the communications lines are still working. I would check both the connection to the modem at the remote site and the Metasys device that it is connected to. It sounds like the Metasys device on site might have lost its programming, had its N2 bus disconnected, or some similar problem.

I have some sites that have N2 Devices. They used to have external modems, were using and aux access program and using external modem. They external modem will dial and connect to modem at site. But when I try to connect to site with hvac pro the site doesnt show any devices. It used to work for years and it just stop working. Any suggestions why?

The Last Resort.

Originally Posted by Cagey57

OP,
This assumes you will find "Legacy N2" devices; AHU's, VMA's, VAV's, UNT and DX-9100's at the job.

The S4 gizmo is trick, the S2 Converter is pretty slick but I already had the B&B 485SD9TB that connect to a 9pin serial port otherwise I would have bought the S2 box. If you do not have a serial port get the B&B converter and a Digi Edgeport/1 to adapt it to a USB port. Least brain damage in the long run.

The software is MW-MTOOL-0 for a new copy (with the CBT) or for about 1/2 the price you should order the MW-MTOOL-6 (no CBT). The AS-CVTPRO300-1 is very pricey. I recommend one of the 2 converters (S2 or the B&B Electroincs) mentioned above. Your best bet will be to locate your local independant Johnson Controls ABCS dealer to order/purchase the M-Tools Software.

You mentioned "Custom Programming", if it's NOT an NAE you will have to decifer the N30 logic or, if its NCM/PMI you will have to get either the JCB source files or the GPL files. Hopefully off of the existing Workstation.

As mentioned above the FX-60/70 is likely your best solution if you don't have a long term plan.

Good Luck.

You purchase the sioftware and hire an ex-jci tech to train you.

http://IP address/sct or http://hostname/sct
u:metasyssysagent
p:XMG3-Rel.1
http://cgproducts.johnsoncontrols.co...DF/1201519.PDF

and if he stuffs it up then somebody from JCI will get a call
...and if he doesnt then ... well, thats the way it should be.

Originally Posted by apprentice3

I have more of a service controls background. I have worked on a lot of different systems out there. I have only done some mild programming. I usually catch on pretty quick once I get going though. So I think some sort of training would be good. I have thought about upgrading this system to a Tridium system. My company hasn't got into Tridium yet, but I have been on them for a few years now letting them know how big of a player Tridium is in the controls market. They are strongly considering sending a few of there programmers, and myself to AX training. I agree this would definitely be the best solution to the problem. On this job there is some pretty custom logic that the JCI system doesn't contain that I would have to put into the Tridium. Do they have a lot of different programming blocks for most applications?

apprentice3... if you want some assistance, please send me a private message. I am in the Columbus, OH area and can help you with whatever you need... figuring out what you have, where you need to go, accessing your current site, etc...



Tommy C...

Originally Posted by alcomech

I wonder if your actual static pressure set point is set too low at the Carrier control panel. At 1.5' W.C. there may not be enough pressure in the duct to the last and final 1st floor. Check the static at you last VAV to verify this. In addition you can get the required velocity set point by using the equal friction method

In addition you will want to balance out a couple of the VMA VAV controllers so that you know what they are doing.
You will need to use the VMA balancing tool through the use of HVAC Pro software or with the use of the VBT VAV balancing tool. If you have gotten into the front end it is possible to verify air flow and static there. But each VMA should have been balanced at start up along with its actual CFM out put and Pick-up gain/coefficient value

Equal Friction Method:
Area (Sq Ft.) = CFM divided by velocity FPM
where as: area = 15000 CFM divided by 1500 FPM = 10 Sq
10 Sq. Ft x 144 (Sq. Inches per Sq. Ft)/24" = 60"
Therefore, select 60"x24" supply duct


5400 CFM ÷ 1700 FPM velocity = 3.18 Sq Ft. Duct Area


Aspect Ratio = 48/12= 4
Aspect Ratio 4 = 144%
Round duct = 66%
Differance = 78%

Velocity FPM = airflow CFM/ area in Ft Squared

Velocity x Area = CFM

To Figure CFM by known Sq Ft area and Static Pressure.

External Static Pressure Method:
This called total external static Pressure.
A differential manamoter is used to measure the air pressure at the inlet and outlet of the blower assembly. This pressure is the same pressure a balloon has pushing against its internal walls. Air Blowers have the same type of pressure at the inlets and outlets. The measured air is compared to design charts provided by the equipment manufacture to determine how much air volume is flowing in cubic feet per minute. (CFM).

Wow this is a lot of information. Thanks for all of you help. Next week I will get into the VAVs and review some of there setpoints. I was also looking into this SCT software on JCIs website. Is that software absolutely necessary to view the logic? Would JCI typically leave that on the end users main computer?

Originally Posted by alcomech

Sounds like you are on to something here. Have you checked the maximum static pressure set point which will put the unit in alarm.
And if so what is the set point.

Also were is the static pressure transducer/ or velocity pick up located at. It should be located 2/3 down stream of the unit so that it will maintain true static to the last VAV's

The maximum static pressure setpoint that will put the unit into alarm is 3" w.c.

The location of the static pressure pick ups are definitely problems. It is right off the discharge of each unit. So basically each unit has its own pick up. I know that this is definitely a problem. I told the customer yesterday about installing one pick up 2/3 down the duct and referencing that one value back up to all 3 units.

I wonder if your actual static pressure set point is set too low at the Carrier control panel. At 1.5' W.C. there may not be enough pressure in the duct to the last and final 1st floor. Check the static at you last VAV to verify this. In addition you can get the required velocity set point by using the equal friction method

In addition you will want to balance out a couple of the VMA VAV controllers so that you know what they are doing.
You will need to use the VMA balancing tool through the use of HVAC Pro software or with the use of the VBT VAV balancing tool. If you have gotten into the front end it is possible to verify air flow and static there. But each VMA should have been balanced at start up along with its actual CFM out put and Pick-up gain/coefficient value

Equal Friction Method:
Area (Sq Ft.) = CFM divided by velocity FPM
where as: area = 15000 CFM divided by 1500 FPM = 10 Sq
10 Sq. Ft x 144 (Sq. Inches per Sq. Ft)/24" = 60"
Therefore, select 60"x24" supply duct


5400 CFM ÷ 1700 FPM velocity = 3.18 Sq Ft. Duct Area


Aspect Ratio = 48/12= 4
Aspect Ratio 4 = 144%
Round duct = 66%
Differance = 78%

Velocity FPM = airflow CFM/ area in Ft Squared

Velocity x Area = CFM

To Figure CFM by known Sq Ft area and Static Pressure.

External Static Pressure Method:
This called total external static Pressure.
A differential manamoter is used to measure the air pressure at the inlet and outlet of the blower assembly. This pressure is the same pressure a balloon has pushing against its internal walls. Air Blowers have the same type of pressure at the inlets and outlets. The measured air is compared to design charts provided by the equipment manufacture to determine how much air volume is flowing in cubic feet per minute. (CFM).

Sounds like you are on to something here. Have you checked the maximum static pressure set point which will put the unit in alarm.
And if so what is the set point.

Also were is the static pressure transducer/ or velocity pick up located at. It should be located 2/3 down stream of the unit so that it will maintain true static to the last VAV's

[QUOTE=alcomech;14046341]Are you sure that the 3 RTU's are feeding the same supply air duct. I guess this can be done but this is not that common. What kind of building is it. Is it office space, individual tenants, or open areas. How many floor does this building have?
Have you verified actual duct static pressure with a magnehelic gauge, down stream of the duct work and also at the static pressure transducers. And if so what static pressure are you trying to maintain.

The building has 6 floors. I have verified the actual duct pressure with a magnahelic. The static pressure they are trying to maintain is 1.5" w.c. Typically on these type of systems I have noticed that all of the units should reference the same static pressure pick up. At this building they are referencing the internal sensors to the unit. 2 of them a reading pretty close to the actual pressure in the duct. One of them is about 1.2 " w.c. low. I have already made recommendations to fix this problem.

The ramp up time on the three VFDs is identical. The VFD is also currently being controlled internal to the unit as well.

Thanks!

Yes all 3 RTUs do feed into a common duct. Trust me I know that it is not typical. This is a office building with VAVs on the RTUs

I will check into that information. Thanks a lot. As far as the SCT software goes the customer doesn't have that. Where can I get that at? Do I need that software to view all of the internal logic? Or can everything still be done in Internet explorer?