Internet PLC Forum

Hi I do try out ADC function by using variable resistor 5K.
I just assume this

Temp C          Voltage         ADC
-20C               0                  0
+200C            5                  4096

By linear relationship
(T+20)/(200 +20) =(A-0)/(4096-0)
T = (A/4096)*220 - 20

while try with value A=0 , i do get T = -20C and when A=4096 then T = 200C. mathematically correct

In my custom function i do wrote as
B = ADC(1) *220 - 20

When i do adjust the variable to minimum end, do get -20C but in maximum end i do get 900C instead of 220C. May i know what cause the error. Thanks

Hi, Currently i did swap my ports and its works, where RS 485 to PC and COMM 1 to GSM modem. But i would like to know the configuration for as mention above.

While trying out using "PAUSE" command and read out the INPUT$(1) for few times, i did get various results as follows:-
\OA
\OA0K
\OA0K
\0AAT+CPMS?
PMS?
\0A+CPMS: "SM",7,40,"SM",7,40,"SM,7,40
203

From bottom, number 2 is correct results. May i know why i am getting this. Do i have to flush the com buffer every time before send command?

Cheers.  

Hi,  I need to monitor the changes in input and output in ladder. At sametime how I force my output to on or close
Please do advice. Thank you.

Hi, I get the information but

Example in hyperterminal

AT+CPMS?
example i get this
+CPMS: "SM",2,40,"SM",2,40,"SM",2,40
'empty row then
OK

then when i try out
SETBAUD 1,9
Print #1 "AT+CPMS?"
delay 50
A$=INPUT$(1)
delay 50
 i=1
for i = 1 to 70
      delay 50
      if ASC(A$,i)=44
         exit
     endif
next
j=i
j=j+1
for j = j to 70
     delay 50
     if ASC(A$,j)=44
         exit
     endif
next
B$ = mid$(A$,i+1,j-i-1)

Print #1 "AT+CMGS="+CHR$(34)+"+6XXXXXXX"+CHR$(34)
Print #1 B$ +CHR$(26)

I do receive "blank" SMS.After continuously on / off input 1 (i do use on/off switch to input 1 to trigger the function) switch give me all kind of incorrect data expect once "2".
I just want to make sure that i receive correct data before processing.

Even i did try to get Len(A$), reply sms subsequently shows :
1) 1
2) 22
3) 3
4) 2
5) 1
6) 3 etc...

just for info in C# i do receive in this format:-
"AT+CPMS?\r\r\n+CPMS:\"SM\",2,40,\"SM\",2,40\r\n\r\nOK\r\n"
 ???

Hi,

I am going to check my incoming message after interval 2 minutes.
1) After 2 minutes i am going to send command "AT+CPMS?"
    which will help me to indicate the number of SMS received.
The reply will be after send this command is:-
+CPMS:"SM",2,40.... where 2 indicates no of SMS received. I did assign string variable A$ to command receive and take out the no of SMS receive and assign to integer variable A.

A$ = Print#1 "AT+CPMS?"
i = 1
While 1
      B$ = MID$( A$,i,1)
     i=i+1
     If(B$ = ",")  goto @10 : ENDIF
ENDWHILE

@10 A = MID$(A$,i,1)

Please do advice me up to this stage first.
How i can debug this to make sure what i get in A, B$ and A$. Do i need to do convert data type in TBASIC.

Then i can catch up the remaining. Thanks

Hi, i did the connection as this

2 - 3
3 - 2
5 - 5 instead of 9 to 9

Finally i did fabricate the cable from summary DB15 to DB 9

DB 15                     DB9
2                            2
6                            3
7+8 (short)
9                            5
11+12(short)

its works perfectly. Thanks for your supports

  Thank you.