Ramp times

I think I understand ramps. Happy to be corrected.

On a NAC/SHAC, if an object/group is at zero, and I specify a SetCBusLevel to 255 over eight seconds, then the ramp takes eight seconds.

But if a group is zero, and I set it to go to 127 over eight seconds, then the ramp takes four seconds, being the time it would take getting to 127 on its way to an ultimate level 255, which it will never reach.

The same goes for an eight second ramp of 127 to 145, which is an eventual total ramping time of around 0.6 seconds.

So is this correct logic? Ramp = ramp rate, which is not the same as time to transition from one state to another.

School me for why should my thinking be busted.

 

Correct. That's why it's called a ramp 'rate' not a ramp 'time'

 

And "I think I understand" instantly turns into "Yup. I got it." Thanks @Ashley. I can not believe it's been over a decade until I've actually really looked at the detail of a ramp (rate).

 

Some more useless information:
There a 16 ramp rates because the ramp rate is enconded using 4 bits in the protocol.
The intervals are counted in about 16mS increments (can't remember the exact figure), so with a 16 bit counter you have a maximum time interval of 65536 * 16mS = 1048576mS = about 17.5 minutes, which is why 17 minutes is the longest ramp rate. Made it easy to implement in the original (slow) microprocessors of the late 90's.

 

I've actually always wondered this! I'd love a ramp rate less than 4sec

 

so is there any way to produce a ramp rate over the 17.5ish (1020 seconds) minute ramp rate?

 

The longest ramp rate increments the group address by 1 every 4 seconds, so if you want longer ramp rates just use logic and a timer to increment the group address at the appropriate rate. You can use a combination of existing long ramp rates with delays between to stretch them out too.

 

Hi Ashley, what logic and timer are you suggesting to use? toolkit or scripting in SHAC or NAC? i get that if i was to increment group address by 1 say every 16 seconds i could get a ramp rate of about 60 minutes but I'm not sure where you are suggesting to implement this.

 

Hi @Ashley , what logic and timer are you suggesting to use? toolkit or scripting in SHAC or NAC? i get that if i was to increment group address by 1 say every 16 seconds i could get a ramp rate of about 60 minutes but I'm not sure where you are suggesting to implement this.

 

One option would be to create a resident script that runs at the desired increment rate (i.e. 16 seconds). Create a dummy control group address that is the desired final level. Every time the script runs compare the group you are ramping with the control group. If they are different increment or decrement the actual group.

 

So what is the method to increase GA level by '+1' "Desired increment rate" as apposed to a final level? then an increase of '+1' by 16 seconds would work. I haven't been able to find a command for increase level by set amount!!!
I'm sorry to keep asking questions that should seem quite easy to search for answers but I'm only grasping this scripting 1 new task at a time and not getting much luck when searching for answers.

 

Read current value. Add one to it. Write new value.

 

Thank you, I knew I was missing something that was right in front of me.

 

I now have Ramp times closer to my desired outcome, increment ramp up is 4 levels every minute (65 minutes in total) and decrement ramp is 20 levels every minute (12 minutes in total) the problem I'm having is the last increase or decrease if not exactly 4 levels or 20 levels I am getting a "Error Log"

Library cbuslogic:0: Value -15 out of range, must be 0-255
stack traceback:
[C]: in function 'error'
Library cbuslogic: in function '_ConvVal'
Library cbuslogic: in function 'SetCBusLevel'

Can I place a log and read the error and place an action like

if (Value=negative)
then SetCBusLevel(0, 56, 5, 0, 0)
elseif (value =positive)
then SetCBusLevel(0, 56, 5, 255, 0)
end

If so can someone help with how to read "error log" and how to place variable "positive" and "negative"

Code:

SOC= GetCBusMeasurement( 0, 50, 48)

discharge = GetCBusMeasurement( 0, 50, 50)

level = GetCBusLevel(0, 56, 5)

state = GetCBusState(0, 56, 5)



if  ( SOC>85) and ( discharge<250) and (level<255)


        then

            

                -- Set '0/56/5' to "ON" over "?"
                        SetCBusLevel(0, 56, 5, level+4, 1000)

log (SOC,discharge,level, state)
 
                                    elseif ( SOC<90) or ( discharge>500)and (level>1)
                                        then
 
                                                -- Set '0/56/5' to "OFF" over 5 minutes
                                                        SetCBusLevel(0, 56, 5, level-20, 1000)

log (SOC,discharge,level)
 
end

 

error
Library cbuslogic:0: Value -15 out of range, must be 0-255
it is just saying you are attempting to set the value of the object to an value that is not accepted and not between 0-255

what about this, added a bit in there to ensure that a level always in the 0-255 range

SOC= GetCBusMeasurement( 0, 50, 48)

discharge = GetCBusMeasurement( 0, 50, 50)

level = GetCBusLevel(0, 56, 5)

state = GetCBusState(0, 56, 5)



if ( SOC>85) and ( discharge<250) and (level<255) then

-- Set '0/56/5' to "ON" over "?"
level = level + 4

if level > 255 then
level = 255
end

SetCBusLevel(0, 56, 5, level, 1000)

log (SOC,discharge,level, state)

elseif ( SOC<90) or ( discharge>500)and (level>1) then

level = level -20

if level < 0 then
level = 0
end

-- Set '0/56/5' to "OFF" over 5 minutes
SetCBusLevel(0, 56, 5, level, 1000)

log (SOC,discharge,level)

end

 

just checking the elseif does what you want without extra brackets, did you mean it to be

elseif ( SOC<90) or ( ( discharge>500) and (level>1) ) then -- the way it is now, or
elseif ( ( SOC<90) or ( discharge>500) ) and (level>1) then -- needs the extra brackets​

 

Why Lua thinks AND should have a higher precedence than OR is just insane. But then the whole language is so completely screwed up I often think it must have been an April fools joke that someone took seriously.

 

While I will say that LUA is "interesting", SQL, C++, Python and more always give higher precedence to AND over OR, with NOT trumping both. It's kind of a convention.

Not so APL, which if you think LUA is an April Fools gag, check that basket case out! Left to right precendence with scope. So a plus before a multiply does the addition first...

 

Actually C++ does AND/OR left to right like C. SQL isn't a language and python is a toy that makes worse mistakes than Lua .