Setting up Analog Output

Outputs
1

Hi, I have some basic questions about setting up AO and hope for simple answers…
I am trying to set up and test AO on a T3-BB. For familiarisation I want to use a switch SW1 on DI1 to drive a 0-10V AO to a particular fixed value (say 5V).

  1. T3 has DO 1-12 plus AO 1-12. T3000 Output Table shows OUT1 to OUT64.
    Is AO1 the same as OUT13 in table?
    2 I set-up Output table - OUT13 named “AO1”, in Auto, range 0-10V, hardware switch to Auto.
    What is the correct syntax to set the AO to say 5V? I tried the following
    10 IF+ SW1 THEN AO1 = 5.0 — no output from AO1
    I also tried using an intermediate variable.
    20 VAR = 5.0
    30 IF+ SW1 THEN AO1 = VAR
    Line 20 works but still no output from AO1.
    3 What is syntax to set output to (say) 60% when output range is 0-100%
    4 I noticed that after saving/sending code and closing programming window, the next time I look the panel number is inserted as a prefix eg 1AO1. Why is this? Should I have inserted panel number myself?

Help appreciated

2
  1. THere is a column in t3000 which shows the signal type, i’ll put a screen shot later but its to the right and shows DIGITAL or ANALOG I beleive. Note that analog outputs can be set to digital ranges but not vice versa.
    2: Assuming AO is set to 0-100% (10V) range then you would go:
    10 OUT13 = 50
  2. To set the output to 6V you go:
    10 OUT13 = 60
  3. 1AO1: You should give the output a name in the far right hand side of the inputs table, this is the user name for the output. CAll it something like VALV101 or something similar, then its more clear what is going on. 1 is probably just the panel ID, you can wirte programs using any point in the whole building including using points from other controllers so this helps keep things straight. The user name is the way to go though.
1 Like
3

Thank you.
1 The Digital & Analog types had defaulted correctly. Outputs from 25 to 64 are shown as Virtual.
Since I am just doing a simple testing, names are not so important. I realise that when working with real program I/O should have “real-world” labels

2 After changing output range to 0-100%, OUT13 = 50 does give an output voltage - great.
I checked output calibration - see table below program-% vs DMM readings, and different supply voltages:
Supply >> 12Vdc 18Vdc 24Vdc
0% 0V 0V 0V
10% 1.0V 1.0V 1.0V
20% 2.0V 2.0V 2.0V
30% 3.0V 3.0V 3.0V
40% 4.0V 4.0V 4.0V
50% 5.0V 5.0V 5.0V
60% 6.0V 6.0V 6.0V
70% 7.0V 7.0V 7.0V
80% 7.66V 8.0V 8.0V
90% 7.66V 9.0V 9.0V
100% 7.66V 10.0V 10.0V

Clearly, the AO reaches a limit at lower supply voltages within nominated 12-24V range. From my observations it requires at least 15Vdc supply to achieve 10V output on AO. This should be noted in documentation.

4

Yes, the analog outputs require some headroom on the power supply and as you found out the minimum is around 15VDC to get the full 0-10V analog output. I guess we should point this out in the documentation.

Most of the hvac industry is built around 24VAC transformers and that is where our products are targeted.

1 Like
5

Hi Maurice,
No worries.- I will run 24V

A couple of other tiny questions to be going on with…:

  1. the manual says the hot-key to renumber a listing is ctrl-E - but when I use this the current-line moves to the right leaving a blank space but no change to numbers. Is there a different hot-key?
  2. After I “send” a program a dialog box reports success and also shows memory usage out of 2000 bytes. Is this 2kB the allocation for the current section of the program (1 to 16)?
    What is program memory capacity (T3-BB) ??
    Cheers

Brian

6

And another question. 3) what is the maximum range of numbers - integer and floating point ?? (I dont see this in manual)

B

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furness.brian
July 26

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Hi Maurice,
No worries.- I will run 24V

A couple of other tiny questions to be going on with…:

  1. the manual says the hot-key to renumber a listing is ctrl-E - but when I use this the current-line moves to the right leaving a blank space but no change to numbers. Is there a different hot-key?

You are right, this is not implemented in the current T3000, we will get it done. You need to send and then reload the program to renumber for now.

  1. After I “send” a program a dialog box reports success and also shows memory usage out of 2000 bytes. Is this 2kB the allocation for the current section of the program (1 to 16)?

Each program is limited to 2k, if you have larger programs you will need to break them up into sections. Just keep in mind to only program a particular output or variable in a single program. If you have two programs operating on the same output the state of the output is not certain.

What is program memory capacity (T3-BB) ??

For the user programs, there are 16 programs of 2k each so the program space is 32k

Cheers

Brian

8

yet another little query
4) when should I use IF versus IF+ function? The T3000 user manual does not offer guidance
I see some examples in the forum where IF+ is used for switch input checking nad IF used for internal (ie not I/O) logic.
In my own tests there doesnt seem to be any difference.

9

IF+ is a one time ‘edge triggered’ event as its called. When you first press a button or when a schedule changes state you can do something based on that event. Its often used in lighting where you have BOTH momentary switches and schedules controlling the state of the lights. You only want to flip the lights when there’s an event like the hit of a button or a schedule goes off. In between events the system is just sitting there waiting for the next event.

IF+ SCHEDULE THEN START LIGHT1 <This will flip the lights on at the beginning of the schedule.

IF- SCHEDULE THEN START LIGHT1 <This will flip the lights off at the end of the schedule.

IF+ BUTTON1 THEN LIGHT1 = NOT LIGHT1 <This will flip the state of the lights. If they were on before they will go off and vice versa.