/*********************************************************************************
* FreeModbus LINUXTCP Compile ERROR
* 说明：
* 想使用FreeModbus TCP在Ubuntu上进行测试，结果其默认没有打开TCP功能。
*
* 2018-1-2 深圳 南山平山村 曾剑锋
********************************************************************************/
一、参考文档：
. http://pl.comp.lang.c.narkive.com/3s8TevOZ/problem-z-kompilacj
二、报错信息：
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/demo.c:: undefined reference to `eMBTCPInit'
../../modbus/mb.o: In function `eMBInit':
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBRTUStart'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBRTUStop'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBRTUSend'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBRTUReceive'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `vMBPortClose'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBRTUReceiveFSM'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBRTUTransmitFSM'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBRTUTimerT35Expired'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBRTUInit'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBASCIIStart'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBASCIIStop'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBASCIISend'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBASCIIReceive'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `vMBPortClose'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBASCIIReceiveFSM'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBASCIITransmitFSM'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `xMBASCIITimerT1SExpired'
/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP/../../modbus/mb.c:: undefined reference to `eMBASCIIInit'
collect2: error: ld returned exit status
Makefile:: recipe for target 'tcpmodbus' failed
make: *** [tcpmodbus] Error
三、解决办法：
. modified the file "freemodbus/modbus/include/mbconfig.h"
. find the under code
/*! \brief If Modbus ASCII support is enabled. */
#define MB_ASCII_ENABLED ( 1 )
/*! \brief If Modbus RTU support is enabled. */
#define MB_RTU_ENABLED ( 1 )
/*! \brief If Modbus TCP support is enabled. */
#define MB_TCP_ENABLED ( 0 )
/*! \brief The character timeout value for Modbus ASCII.
change into
#define MB_ASCII_ENABLED ( 0 )
#define MB_RTU_ENABLED ( 0 )
#define MB_TCP_ENABLED ( 1 )
四、Compile Output：
root@localhost:/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP# make
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o demo.o -c demo.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o port/portother.o -c port/portother.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o port/portevent.o -c port/portevent.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o port/porttcp.o -c port/porttcp.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/mb.o -c ../../modbus/mb.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/tcp/mbtcp.o -c ../../modbus/tcp/mbtcp.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfunccoils.o -c ../../modbus/functions/mbfunccoils.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfuncdiag.o -c ../../modbus/functions/mbfuncdiag.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfuncholding.o -c ../../modbus/functions/mbfuncholding.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfuncinput.o -c ../../modbus/functions/mbfuncinput.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfuncother.o -c ../../modbus/functions/mbfuncother.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbfuncdisc.o -c ../../modbus/functions/mbfuncdisc.c
gcc -g -Wall -Iport -I../../modbus/rtu -I../../modbus/ascii -I../../modbus/include -I../../modbus/tcp -pthread -o ../../modbus/functions/mbutils.o -c ../../modbus/functions/mbutils.c
gcc demo.o port/portother.o port/portevent.o port/porttcp.o ../../modbus/mb.o ../../modbus/tcp/mbtcp.o ../../modbus/functions/mbfunccoils.o ../../modbus/functions/mbfuncdiag.o ../../modbus/functions/mbfuncholding.o ../../modbus/functions/mbfuncinput.o ../../modbus/functions/mbfuncother.o ../../modbus/functions/mbfuncdisc.o ../../modbus/functions/mbutils.o -lpthread -o tcpmodbus
root@localhost:/home/zengjf/freemodbus/freemodbus-v1.5.0/demo/LINUXTCP#