SEND_STRING issue

ubernyako

Alright, so I do AMX from time to time, and this time it was after really really long break, had an issu about this:

DEFINE_CONSTANT
CHAR MitsubishiON232[] =  "'00vP 1',$0D" 
// ...
// And after some code
SEND_STRING dvVidWall232, MitsubishiON232

doesn't work. But this:

SEND_STRING dvVidWall232, "'00vP 1',$0D" 

works just fine. Unfortunatelly I didn't screencap the notification messages, but strings sent to device were the same. The result is totally different though. Point me where I'm wrong here please

Joe Hebert

ubernyako wrote: »

I didn't screencap the notification messages, but strings sent to device were the same. The result is totally different though.

Take a closer look at the Notifications and you’ll see that the strings sent to the device were not the same.

You’re first example:
Line 1 (05:14:02):: String To [5001:1:111]-

You’re second example
Line 3 (05:14:02):: String To [5001:1:111]-[00vP 1$0D]

Drop you constant into debug and you’ll see that it has a length of 12 and not the 7 characters you are expecting.

DHawthorne

NetLinx does some strange things when handling strings ... they don't have an actual string variable type, it's a char array, but some, and only some, of their functions treat it like a string, and some like an array.

Try this:

SEND_STRING dvVidWall232, "MitsubishiON232"

Putting quotes around your variable tells the command explicitly that it's a string, and will be handled that way in terms of glyph translation, etc. I think what's happening is without the quotes it's handling the imbedded ' marks as literal characters, not as 'whatever is inside these is ASCII'.

Joe Hebert

If you change this:
CHAR MitsubishiON232[] = "'00vP 1',$0D"

To this:
CHAR MitsubishiON232[] = {'0','0','v','P',' ','1',$0D}

it will work the way you intended.

Hedberg

The basic problem is that he's trying to define a constant using a string expression. Look at this:

DEFINE_CONSTANT
CHAR MitsubishiON232[] =  "'00vP 1',$0D" 

the RHS of the declaration/definition IS NOT a constant, it's a string expression. Apparently, the compiler interprets everything inside the double quotes as a string literal.

Joe Hebert

Tech Note 531

How to Initialize Character Strings in the DEFINE_CONSTANT and DEFINE_VARIABLE Sections

http://amx.com/techsupport/techNote.asp?id=531

vining

If you're a dumb a$$ like me it might be helpful to create another DEFINE_CONSTANT section before all the other CONSTANT sections ( if you're into multiples too) and place a commented out version of the technote in it. Despite how many times I do these I always find myself going back to a previously written sections of code to see how I did it last time.

This post reminded me that I always struggle with this question so I just added it to my current system and it will become part of all future systems like I do with this:

PROGRAM_NAME= 'VAV_Xxxxxxxxxx'
DEFINE_DEVICE   //#WARN 'TELNET MASTER & set udp bc rate 0'.......ETC.......

#WARN 'TELNET MASTER & set udp bc rate 0'
#WARN 'TELNET MASTER & set zeroconf disable'
#WARN 'TELNET MASTER & set duet memory 18m'
#WARN 'TELNET MASTER & set ssh port 0'
#WARN 'TELNET MASTER & set ethernet mode 10 full'

in all systems. The more reminders for me the better!

Folded & Unfolded screenshots....