Timeout Issue

[sowmyam123]

I integrated NanoModbus library with the quectel EC200u controller for RTU communication as a master. However, I'm encountering timeout errors despite successful communication. In the SDK, there isn't a timer function available to handle read and write operations. Could you please assist me in resolving this issue?

[debevv]

Sure, can you post your read and write functions?
In general, from the README:

A value < 0 for byte_timeout_ms means no timeout.
Their return value should be the number of bytes actually read/written, or < 0 in case of error.
A return value between 0 and count - 1 will be treated as if a timeout occurred on the transport side. All other values will > be treated as transport errors.

So if you can't honor the requested timings, you can just return the exact number of byte requested and you should never encounter any timeout error

[sowmyam123]

Thanks for quick Answer

Please review the read and write code below along with the logs.

This code executes a read operation without incorporating any time delay handling between read and write operations. Upon request, we print the return value, which consistently shows -3.This indicate a read/write timeout error? How can we resolve this timeout issue? The read operation should function properly without resorting to alternatives.

Could you please assist me in resolving this issue?

Logs:

ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 25
ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 0
ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 25
ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 0
ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 25
ql_rs485_demo:ql_rs485_read 206 entered ql_rs485_read read_bytes: 0

ql_rs485_demo:ql_rs485_demo_thread 371 Error1 in reading1: -3

Code:-
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "ql_api_osi.h"
#include "ql_log.h"
#include "ql_uart.h"
#include "ql_gpio.h"
#include "ql_pin_cfg.h"
#include "nanomodbus.h"

ql_task_t rs485_task = NULL;
nmbs_t nmbs;

int ql_rs485_write(ql_uart_port_number_e port, unsigned char *data, unsigned int data_len)
{
int write_len = 0;
ql_uart_tx_status_e tx_status;
ql_uart_errcode_e ret;

ql_gpio_set_level(QL_RS485_GPIO_NUM, LVL_HIGH);
 QL_RS485_DEMO_LOG("entered ql_rs485_write : %d ", data_len);
write_len = ql_uart_write(QL_UART_PORT_1, data, data_len);
QL_RS485_DEMO_LOG("entered ql_rs485_write write_len : %d ", write_len);
while(1)
{
     QL_RS485_DEMO_LOG("entered write while loop : ");
    ret = ql_uart_get_tx_fifo_status(QL_UART_PORT_1, &tx_status);
    if(ret)
    {
        break;
    }
    if(tx_status == QL_UART_TX_COMPLETE)
    {
        break;
    }
}
for(int i = 0; i < write_len; i++)
{
    QL_RS485_DEMO_LOG("sent byte %d: 0x%02X", i, data[i]);
}
ql_gpio_set_level(QL_RS485_GPIO_NUM, LVL_LOW);

return write_len;

}

int ql_rs485_read(ql_uart_port_number_e port, unsigned char *data, unsigned int data_len)
{
ql_gpio_set_level(QL_RS485_GPIO_NUM, LVL_LOW);
QL_RS485_DEMO_LOG("entered ql_rs485_read : %d ", data_len);
time_t start_time = time(NULL);
int read_bytes = ql_uart_read(QL_UART_PORT_1, data, data_len);

// Log the received data in hexadecimal format
for(int i = 0; i < read_bytes; i++)
{
    QL_RS485_DEMO_LOG("Received  %d: 0x%02X", i, data[i]);
}
 QL_RS485_DEMO_LOG("entered ql_rs485_read read_bytes : %d ", read_bytes);
 time_t current_time = time(NULL);
 if(current_time -  start_time >= 1)
 {
    QL_RS485_DEMO_LOG("Timeout occured :  ");
 }

return read_bytes;

}

int32_t read_serial(uint8_t* buf, uint16_t count, int32_t byte_timeout_ms, void* arg)
{

QL_RS485_DEMO_LOG("Received byte_timeout_ms1 %d:", byte_timeout_ms);


return ql_rs485_read(QL_UART_PORT_1, buf, count);

}

int32_t write_serial(const uint8_t* buf, uint16_t count, int32_t byte_timeout_ms, void* arg)
{

 QL_RS485_DEMO_LOG("Received byte_timeout_ms2 %d:", byte_timeout_ms);


return ql_rs485_write(QL_UART_PORT_1, (unsigned char*)buf, count);

}

static void ql_rs485_demo_thread(void *param)
{
int ret = 0;
QlOSStatus err = 0;

ql_uart_config_s uart_cfg = {0};

uint32_t event_mask = 0;



ret = ql_pin_set_func(QUEC_PIN_DNAME_GPIO_18, 0);
if(QL_GPIO_SUCCESS != ret)
{
    goto exit;
}
ql_gpio_deinit(QL_RS485_GPIO_NUM);
ql_gpio_init(QL_RS485_GPIO_NUM, GPIO_OUTPUT, QUEC_PIN_NONE, LVL_LOW);

//step3:set event mask
event_mask = QL_UART_EVENT_RX_ARRIVED | QL_UART_EVENT_RX_OVERFLOW;
ret = ql_uart_set_event_mask(QL_UART_PORT_1, event_mask);
if(QL_UART_SUCCESS != ret)
{
	goto exit;
}

//step4:rs485 init, baud rate and other parameters need to be configured
uart_cfg.baudrate = QL_UART_BAUD_115200;
uart_cfg.flow_ctrl = QL_FC_NONE;
uart_cfg.data_bit = QL_UART_DATABIT_8;
uart_cfg.stop_bit = QL_UART_STOP_1;
uart_cfg.parity_bit = QL_UART_PARITY_NONE;


 nmbs_platform_conf platform_conf;
    platform_conf.transport = NMBS_TRANSPORT_RTU;
  platform_conf.read = read_serial;
   platform_conf.write = write_serial;

  
    nmbs_error error1 = nmbs_client_create(&nmbs, &platform_conf);
     QL_RS485_DEMO_LOG("error1 = %d",error1);
    if (error1 != NMBS_ERROR_NONE)
    {
        QL_RS485_DEMO_LOG("Error ");
    }

     nmbs_set_read_timeout(&nmbs, 1000);
     nmbs_set_byte_timeout(&nmbs, 100);
     nmbs_set_destination_rtu_address(&nmbs, RTU_SERVER_ADDRESS);

ret = ql_rs485_init(QL_UART_PORT_1, &uart_cfg, ql_rs485_notify_cb);
if(ret)
{
	goto exit;
}

while(1)
{


     uint16_t r_regs[10];
    error1 = nmbs_read_holding_registers(&nmbs, 4, 10, r_regs);
    if (error1 != NMBS_ERROR_NONE && error1 == NMBS_ERROR_TIMEOUT)
    {
        QL_RS485_DEMO_LOG("Error1 in reading1 : %d",error1);
    }
  else if(error1 == NMBS_ERROR_NONE)
    {
           QL_RS485_DEMO_LOG("No error reading1 : %d",error1);
    }    


ql_rtos_task_sleep_ms(1000); // Example: Delay for 1 second (1000 milliseconds)

}

exit:
QL_RS485_DEMO_LOG("ret: 0x%x", ret);
err = ql_rtos_task_delete(NULL);
if(err != QL_OSI_SUCCESS)
{
QL_RS485_DEMO_LOG("task deleted failed");
}
}