SET_VIRTUAL_PORT_COUNT ??

KielL

Hello everyone,

I just inherited a program that might have a potential bug lurking in it somewhere. As I've been going over it, I found in the DEFINE_EVENT section of the main program:

data_event[33001:1:0]
{
  online:
	{
	  set_virtual_port_count(data.device,15)
	}
}

I've never used SET_VIRTUAL_PORT_COUNT, and it isn't in the NetLinx documentation either it seems. I'm guessing by the name that it sets a port count for a virtual device, but I'm wondering why that is even needed really. Has anybody else ever used this function? Is there any benefit?

Many thanks for the help!

jjames

By default I believe virtuals use up to 256 channels. If you ever needed to go above that, you would use SET_VIRTUAL_PORT_COUNT. There's been cases to where setting it was needed for the R4 - but I forget the details.

I'm confused as to why one would set it to 15 when 256 it should work out of the box.

KielL

I'm probably going to remove it from this program since it (likely) has no benefit. Just one less thing to look at when I have to go on-site to troubleshoot.

Thank you for the help, jjames!

Spire_Jeff

SET_VIRTUAL_PORT_COUNT is necessary for the processor to track channel/level states for port above 1 (According to the help file). If you remove this, it is possible that feedback and or functionality will be adversely affected.

Here is the section the NetLinx Keywords Help file:

SET_VIRTUAL_PORT_COUNT
Lets the programmer override the default number of ports that a virtual device maintains. By default every virtual device maintains the state of a single port (port 1).

SET_VIRTUAL_PORT_COUNT(DEV Device, INTEGER Count)

Parameters:

Device - the virtual device to modify.

Count - the number of ports that the specified virtual device should maintain.

Returns: None

Example:

SET_VIRTUAL_PORT_COUNT (dvVirtual,2) // 2 ports

See Also

SET_DNS_LIST

SET_IP_ADDRESS

SET_LENGTH_ARRAY

SET_LENGTH_STRING
SET_OUTDOOR_TEMPERATURE
SET_PULSE_TIME
SET_SYSTEM_NUMBER
SET_TIMER

SET_VIRTUAL_CHANNEL_COUNT
SET_VIRTUAL_LEVEL_COUNT

As you can see, there is also a SET_VIRTUAL_CHANNEL_COUNT and SET_VIRTUAL_LEVEL_COUNT. Channels default to 255 and levels to 8. I would recommend NOT removing it unless you are sure you don't need it.

Jeff

jjames

Jeff - thanks for the clarification of my bad information. I obviously got SET_VIRTUAL_CHANNEL_COUNT and SET_VIRTUAL_PORT_COUNT mixed up.

*oops!*

AMXJeff

jjames wrote: »

Jeff - thanks for the clarification of my bad information. I obviously got SET_VIRTUAL_CHANNEL_COUNT and SET_VIRTUAL_PORT_COUNT mixed up.

*oops!*

I was going to say... It is not wise to remove code from a program on the grounds that you do not understand why it was there. Surfice it to say, programmers tend not to add code just to add code...

jjames

AMXJeff wrote: »

I was going to say... It is not wise to remove code from a program on the grounds that you do not understand why it was there. Surfice it to say, programmers tend not to add code just to add code...

Agreed! Like I said, obviously got the CHANNEL & PORT mixed up and was confused why one would set it lower than the default.

I never advised him to remove it.

KielL

Thanks for the clarification, guys!

vining

SET_VIRTUAL_PORT_COUNT is your friend and I use it all the time. Of course using multiple ports on a single virtual number opens up other problems but if you are going above one port on the same vDev.number it's a must use item.

mush

KielL wrote: »

data_event[33001:1:0]
{
  online:
	{
	  set_virtual_port_count(data.device,15)
	}
}

Should there also be a REBUILD_EVENT() in there?