Need help with Modbus

[pashanoid]

A great localtime to everyone!

Please help me figure out which (and how) of the few available Perl Modbus modules to use! I can't seem to figure out coils, registers and addresses. However, this piece of c code (when compiled with modbus libraries) works fine:

/*
 *  sunsaver.c - This program reads all the RAM registers on a Morings
+tar SunSaver MPPT and prints the results.
 *
*/


/* Compile with: cc sunsaver.c -o sunsaver -lmodbus */

#include <stdio.h>
#include <stdlib.h>
#include <modbus/modbus.h>

#define SUNSAVERMPPT    0x01    /* MODBUS Address of the SunSaver MPPT
+ */

int main(void)
{
        modbus_param_t mb_param;
        int ret;
        float adc_vb_f,adc_va_f,adc_vl_f,adc_ic_f,adc_il_f, Vb_f, Vb_r
+ef, Ahc_r, Ahc_t, kWhc;
        float V_lvd, Ahl_r, Ahl_t, Power_out, Sweep_Vmp, Sweep_Pmax, S
+weep_Voc, Vb_min_daily;
        float Vb_max_daily, Ahc_daily, Ahl_daily, vb_min, vb_max, V_PU
+, I_PU;
        short T_hs, T_batt, T_amb, T_rts;
        unsigned short charge_state, load_state, led_state;
        unsigned int hourmeter;
        unsigned short array_fault, load_fault, dip_switch, array_faul
+t_daily, load_fault_daily;
        unsigned int alarm, alarm_daily;
        uint16_t data[150];

        /* Setup the serial port parameters */
//      modbus_init_rtu(&mb_param, "/dev/tty.voltmeter", 9600, "none",
+ 8, 2);   /* Add the appropriate path to your serial port */
        modbus_init_tcp(&mb_param, "192.168.0.57", 502);/* Add the app
+ropriate path to your serial port */

        /* Open the MODBUS connection */
        if (modbus_connect(&mb_param) == -1) {
                printf("ERROR Connection failed\n");
                exit(1);
        }

        /* Read the RAM Registers */
        ret = read_input_registers(&mb_param, SUNSAVERMPPT, 0x0000, 75
+, data);

        /* Close the MODBUS connection */
        modbus_close(&mb_param);

        /* Convert the results to their proper values and print them o
+ut */
        V_PU=((data[1] << 16) + data[0]);
//      printf("%.2f\n",V_PU);
        I_PU=((data[3] << 16) + data[2]);

        printf("%.2f\n%.2f\n",data[59]*V_PU*I_PU/131072,data[58]*V_PU*
+I_PU/131072); 
//max P
//        printf("%.2f\n",data[60]*V_PU*I_PU/131072);

        //array V, batteryV
        printf("%.2f\n%.2f\n",data[27]*V_PU/32768,data[38]*V_PU/32768)
+;
        printf("%d\n",data[55]);

        return(0);
}

I've looked into: http://search.cpan.org/search?mode=all&query=Modbus all of these, and I'm giving up. I wrote a perl program that uses the above code to get the dreaded 4 values from this solar controller, but this is not right! Anyone, with experience with Modbus, please help me use the propper module and get the abouve 4 (and hopefully more) values directly from Perl!

[Khen1950fx]

Protocol::Modbus is the module that you want to use. The documentation is very sparse, but the source has the info that you need. I gave it quick look and managed to get this going. I used the generic approach.

#!/usr/bin/perl -l

use strict;
use warnings;

$|=1;

my $proto = Protocol::Modbus->new( driver => 'TCP',  transport => 'TCP
+' );

my $request1 = $proto->request(
    function => 1,
    address  => 1,
    quantity => 1,
);

my $request2 = $proto->request(
   function  => 2,
   address   => 1,
   quantity  => 1,
);

my $request3 = $proto->request(
   function  => 3,
   address   => 1,
   uantity   => 1,
);

my $request4 = $proto->request(
   function  => 4,
   address   => 1,
   quantity  => 1,
); 

print "=" x 60;
print "Using unpack: \n";
print unpack ('H*', $request1->pdu());
print unpack ('H*', $request2->pdu());
print unpack ('H*', $request3->pdu());
print unpack ('H*', $request4->pdu());
print "=" x 60;
print "Using Pretty-Print: \n";
print $request1;
print $request2;
print $request3;
print $request4;
print "=" x 60;
print "stringify: ";
print $request1->stringify();
print $request2->stringify();
print $request3->stringify();
print $request4->stringify();
print "=" x 60;

[pashanoid]

Thank you! However, could you please elaborate: if my IP is 192.168.0.57 port 502, then do I format the like this? $proto = Protocol::Modbus->new( driver => 'TCP', transport => 'TCP', ip=>'192.168.0.57', port=>'502' );

if in c ret = read_input_registers(&mb_param, SUNSAVERMPPT, 0x0000, 75, data); Then Which are the function, address and quantity? in my $request4 = $proto->request( function => 4, address => 1, quantity => 1, );

Which handle/variable gets the modbus reply?

[Khen1950fx]

The $req variable gets the modbus reply.

#!/usr/bin/perl -l

use strict;
use warnings;
use Protocol::Modbus;

$|=1;

my $modbus = Protocol::Modbus->new(
    driver    => 'TCP',
    transport => 'TCP',
);

my $trs = Protocol::Modbus::Transport->new(
    driver  => 'TCP',
    address => '192.168.0.57',
    port    => 502,
    timeout => 3,
);

my $req = $modbus->request(
    function => 4,
    address  => 1,
    quantity => 75,
    value    => 0x0000,
);
print "=" x 60;
print "Response: ", $req;
print "=" x 60;
$trs->disconnect;