COM-port initialization file format

This file is written in text format and consists from several sections. The order of this sections doesn't important. Every section starts with header like this --

[<section_name>]

and lasts until next section starts or until the end of file. Every section content several records. The record has this format --

<record_name>=<value>;

These sections should be described in the file: init, sample, var, var.scale (not nessesarly) , var.display (not nessesarly).

Variables are described in var section. Variable names can de substituted in the record values with $ sign. In the case when section var.scale is exist, in this section scale coefficients for conversion of variables values to numbers can be set. Then values, multiplied to these scale coefficients, will appear in a Parametres window of the client's software.

If the var.display section is exist, the alternate, more convenient variables names, can be set in the section. The section init have to contain following records:

• RdInterval - maximum interval (in milliseconds) between two consecutive symbols that was read from a port.
• RdTotMult - maximum time of reading for one symbol.
• RdTotConst - reading constant; Program cancel reading for a string containing N symbols from a port due to time-out if reading time exceeds N*RdTotMult+RdTotConst, or interval between reading of two consecutive symbols exceeds RdInterval.

• WrTotMult - maximum time of writing for one symbol.
• WrTotConst - writing constant.
• Speed - equation, that set maximum data reading speed (in Hz). Variables, numbers, operations + - * / and brackets ( ) can be used in this equation. Multiplication and division operations has a higher priority than addition and subtraction.
• init - Device initialization string; the string consist of numeric values, delays and escape-functions, divided by commas. Numeric values can be decimal (like 123), Hex (0xa1) or Oct (0175) format. Every numeric value corresponds to one byte of information to be send. Delay should be written as !<time in milliseconds>, for example !500. Escape-function is one of following values:
  • CLRDTR
  • CLRRTS
  • SETDTR
  • SETRTS
  • SETXOFF
  • SETXON
  • SETBREAK
  • CLRBREAK
• init_read - Number of bytes needed to be read after string init have been sent.

Section sample should contain following records:

• init - single string, contain loading initialization values. String must consist only from numeric values, divided by commas.
• init_read - number of bytes, that needed to be read after the string init is sent.
• lobyte - value's low byte loading initialization string.
• lobyte_read - number of bytes, that needed to be read after the string lobyte is sent.
• lobyte_offset - value of string's low byte offset, can be negative.
• hibyte - value's high byte loading initialization string.
• hibyte_read - number of bytes, that needed to be read after the string hibyte is sent.
• hibyte_offset - value of loaded string's high byte offset, can be negative.

Communication with a port goes according to following scenario:

• If additional data channel is enabled (2.1.2) during DSP board initialization it sends strings [init]init to chosen COM-port and reads [init]init_read bytes.

• During image acquiring in every acquired point program sending string [sample]init to a port and reading [sample]init_read bytes from it. After reading is done, it send [sample]lobyte string and read [sample]lobyte_read bytes. From the loaded data, length of which is [sample]init_read + [sample]lobyte_read+[sample]hibyte_read, it take two bytes with offsets [sample]init_read + [sample]lobyte_offset and [sample]init_read + [sample]lobyte_read + [sample]hibyte_offset, and from these bytes it form 16-bit result.

An example of initialization file listed below.

[init]
RdInterval=500;
RdTotConst=500;
RdTotMult=500;
Speed=1.0/(2.0e-6*$CCPR2*$TMRQuanta);
WrTotConst=0;
WrTotMult=0;
init=SETRTS,!100,CLRRTS,!100,0x74,$Uhv,0xf4,0x74,$Ud,0xfc;
init_read=6;

[sample]
hibyte=0xa6;
hibyte_offset=0;
hibyte_read=1;
init=0x30,$C_DvdReg,0x1c,$CCPR2High,0x1b,$CCPR2Low,0x29,$TMRQuanta,0xf2;
init_read=9;
lobyte=0x81;
lobyte_offset=0;
lobyte_read=1;

[var]
CCPR2(Cntr),int,0,0xffff=256;
CCPR2High,int,0,255,,#CCPR2 >> 8=#CCPR2 >> 8;
CCPR2Low,int,0,255,,#CCPR2 & 0xff=#CCPR2 & 0xff;
C_DvdReg(Div),int,0,255=0;
TMRQuanta(Cntr T, ms),int,0,255,0.05*##=40;
Ud(Ud, V),int,0,255=20;
Uhv(Uhv, V),int,0,255=200;
sample_freq,double,,,,,1.0/(2.0e-6*#CCPR2*#TMRQuanta)=1;