This thread has been very helpful to me so far, but I haven't seen any lists for newer KRC4 controllers:
http://www.robot-forum.com/rob…_subprograms-t2002.0.html
In WorkVisual, at least in v4.0.17, you can "Go to declaration" on most system functions which opens up a write protected $OPERATE.dat or $OPERATE_2.dat (that I have found so far), which list all the system declarations of variables, structures, enumerations and functions. I have listed the functions I have found below.
EXTP DELETE_BACKWARD_BUFFER ( )
EXTFCTP INT DIAG_START(DIAGPAR_T PAR :OUT,DIAGOPT_T OPT :OUT)
EXTFCTP INT DIAG_STOP()
EXTFCTP EDIAGSTATE GET_DIAGSTATE()
EXTFCTP BOOL GETSYSSTATE(CHAR CMD[64] :IN,INT IPAR :OUT,REAL RPAR :OUT)
EXTFCTP BOOL IS_KEY_PRESSED(INT KEY :IN)
EXTFCTP CHAR GETCYCDEF(INT INDEX :IN)
EXTFCTP CHAR GET_DECL_PLACE(CHAR VARNAME[80] :IN)
EXTFCTP INT CHECKPIDONRDC()
EXTFCTP RW_RDC_FILE PIDTORDC(CHAR STRVAR[470] :IN)
EXTFCTP RW_RDC_FILE DELETE_PID_ON_RDC()
EXTFCTP RW_RDC_FILE CAL_TO_RDC()
EXTFCTP RW_MAM_FILE SET_MAM_ON_HD(E6AXIS VALUES :IN)
EXTFCTP RW_MAM_FILE COPY_MAM_HD_TO_RDC()
EXTFCTP RW_RDC_FILE CREATE_RDC_ARCHIVE()
EXTFCTP RW_RDC_FILE RESTORE_RDC_ARCHIVE()
EXTFCTP RW_RDC_FILE DELETE_RDC_CONTENT()
EXTFCTP RW_RDC_FILE RDC_FILE_TO_HD(CHAR FILENAME[128] :IN)
EXTFCTP INT CHECK_MAM_ON_RDC()
EXTFCTP RDC_FS_STATE GET_RDC_FS_STATE()
EXTFCTP INT SET_SYSTEM_DATA(CHAR OWNER_NAME[16] :IN,CHAR OWNER_AXNAME[5] :IN,CHAR VAR_NAME[64] :IN,REAL VALUE :IN)
EXTFCTP INT SET_SYSTEM_DATA_DELAYED(CHAR OWNER_NAME[16] :IN,CHAR OWNER_AXNAME[5] :IN,CHAR VAR_NAME[64] :IN,REAL VALUE :IN)
EXTFCTP REAL GET_SYSTEM_DATA(CHAR OWNER_NAME[16] :IN,CHAR OWNER_AXNAME[5] :IN,CHAR VAR_NAME[64] :IN,INT STATUS :OUT)
EXTP ERR_CLEAR (ERROR_T PERR :OUT )
EXTP ERR_RAISE (ERROR_T PERR :OUT )
EXTFCTP REAL ABS(REAL X :IN)
EXTFCTP REAL SQRT(REAL X :IN)
EXTFCTP REAL SIN(REAL X :IN)
EXTFCTP REAL COS(REAL X :IN)
EXTFCTP REAL TAN(REAL X :IN)
EXTFCTP REAL ACOS(REAL X :IN)
EXTFCTP REAL ATAN2(REAL X :IN,REAL Y :IN)
EXTFCTP INT MBX_REC(INT MBX_ID :IN,STOPMESS MESS :OUT)
EXTFCTP FRAME TOOL_ADJ(FRAME X :OUT)
EXTFCTP FRAME EK(FRAME TKRWE :IN,ESYS EXKIN :IN,FRAME TBAFL :IN)
EXTFCTP FRAME LK(FRAME ROOT :IN,CHAR IP_ADDR[24] :IN,FRAME OFFSET :IN,ESYS EXKIN :IN)
EXTFCTP E6AXIS INVERSE(E6POS TOOLPOS :IN,E6AXIS START_AXIS :IN,INT STATUS :OUT)
EXTFCTP E6POS FORWARD(E6AXIS AXVAL :IN,INT STATUS :OUT)
EXTFCTP E6POS INV_POS(E6POS POS_VALUES :IN)
EXTFCTP INT IOCTL(CHAR DRVNAME[256] :IN,INT REQUEST :IN,INT ARGUMENT :IN)
EXTFCTP INT CIOCTL(INT HANDLE :IN,INT REQUEST :IN,INT ARGUMENT :IN,CHAR PARAM[128] :IN,INT RETVAL :OUT)
EXTFCTP INT SYNC()
EXTFCTP VAR_STATE VARSTATE(CHAR VAR_STR[80] :IN)
EXTFCTP BOOL WSPACEGIVE(INT SPACEID :IN)
EXTFCTP BOOL WSPACETAKE(INT SPACEID :IN,INT ADVANCE :IN)
EXTP SYNCCMD (SYNCTYPE SYNC_T :IN,CHAR ID_NAME[64] :IN,INT COOP_LIST :IN )
EXTFCTP RET_C_PSYNC_E CANCELPROGSYNC(CANCEL_PSYNC_E CMD :IN,CHAR ID_NAME[64] :IN)
EXTFCTP BOOL REMOTECMD(CHAR IP_ADDR[24] :IN,CHAR CMD[128] :IN)
EXTFCTP CHAR REMOTEREAD(CHAR IP_ADDR[24] :IN,CHAR VARIABLE[128] :IN,INT ERROR :OUT)
EXTFCTP INT STRLEN(CHAR STRVAR[2047] :IN)
EXTFCTP INT STRDECLLEN(CHAR STRVAR[2047] :OUT)
EXTFCTP BOOL STRCLEAR(CHAR STRVAR[2047] :OUT)
EXTFCTP INT STRADD(CHAR STRDEST[2047] :OUT,CHAR STRTOADD[2047] :IN)
EXTFCTP INT STRFIND(INT STARTAT :IN,CHAR STRVAR[2047] :IN,CHAR STRFIND[2047] :IN,CASE_SENSE_T CASE_MODE :IN)
EXTFCTP BOOL STRCOMP(CHAR STRCOMP[2047] :IN,CHAR STRCOMP2[2047] :IN,CASE_SENSE_T CASE_MODE :IN)
EXTFCTP BOOL STRCOPY(CHAR STRDEST[2047] :OUT,CHAR STRSOURCE[2047] :IN)
EXTFCTP BOOL ISMESSAGESET(INT MESSAGENO :IN)
EXTFCTP BOOL TIMER_LIMIT(REAL SECONDS :IN)
EXTFCTP INT SET_KRLMSG(EKRLMSGTYPE TYPE :IN,KRLMSG_T MSG :OUT,KRLMSGPAR_T PAR[3] :OUT,KRLMSGOPT_T OPT :OUT)
EXTFCTP BOOL EXISTS_KRLMSG(INT NHANDLE :IN)
EXTFCTP BOOL CLEAR_KRLMSG(INT NHANDLE :IN)
EXTFCTP INT SET_KRLDLG(KRLMSG_T MSG :OUT,KRLMSGPAR_T PAR[3] :OUT,KRLMSGDLGSK_T SK[7] :OUT,KRLMSGOPT_T OPT :OUT)
EXTFCTP BOOL SET_KRLDLGANSWER(INT NHANDLE :IN,INT ANSWERSK :IN)
EXTFCTP BOOL EXISTS_KRLDLG(INT NHANDLE :IN,INT ANSWER :OUT)
EXTFCTP INT GET_MSGBUFFER(MSGBUF_T MSGBUF[100] :OUT)
EXTFCTP BOOL STRTOREAL(CHAR STRVAR[256] :IN,REAL RETVAL :OUT)
EXTFCTP BOOL STRTOBOOL(CHAR STRVAR[256] :IN,BOOL RETVAL :OUT)
EXTFCTP BOOL STRTOINT(CHAR STRVAR[256] :IN,INT RETVAL :OUT)
EXTFCTP BOOL STRTOSTRING(CHAR STRVAR[256] :IN,CHAR RETVAL[256] :OUT)
EXTFCTP BOOL STRTOFRAME(CHAR STRVAR[256] :IN,FRAME RETVAL :OUT)
EXTFCTP BOOL STRTOPOS(CHAR STRVAR[256] :IN,POS RETVAL :OUT)
EXTFCTP BOOL STRTOE3POS(CHAR STRVAR[256] :IN,E3POS RETVAL :OUT)
EXTFCTP BOOL STRTOE6POS(CHAR STRVAR[256] :IN,E6POS RETVAL :OUT)
EXTFCTP BOOL STRTOAXIS(CHAR STRVAR[256] :IN,AXIS RETVAL :OUT)
EXTFCTP BOOL STRTOE3AXIS(CHAR STRVAR[256] :IN,E3AXIS RETVAL :OUT)
EXTFCTP BOOL STRTOE6AXIS(CHAR STRVAR[256] :IN,E6AXIS RETVAL :OUT)
EXTFCTP VAR_TYPE VARTYPE(CHAR VAR_STR[80] :IN)
EXTFCTP REAL FRAND(REAL MIN_VAL :IN,REAL MAX_VAL :IN)
EXTFCTP INT GETVARSIZE(SYS_VARS MESSAGENO :IN)
EXTFCTP INT MAXIMIZE_USEDXROBVERS()
EXTFCTP INT SET_USEDXROBVERS(INT MAJORVERS :IN,INT MINORVERS :IN)
EXTFCTP INT SET_OPT_FILTER(E6POS TARGETPOS :IN)
EXTP MD_SETSTATE (CHAR DEVNAME[39] :IN,MD_STATE STATE :IN )
EXTFCTP MD_STATE MD_GETSTATE(CHAR DEVNAME[39] :IN)
EXTFCTP INT MD_CMD(CHAR DEV_NAME[39] :IN,CHAR CMD_STRING[64] :IN,INT INT_PARAM[16] :OUT,REAL REAL_PARAM[16] :OUT)
EXTP MD_ASGN (CHAR DEV_NAME[39] :IN,CHAR KEY_STRING[64] :IN,CHAR VALUE_STRING[64] :IN )
EXTFCTP FRAME EB(FRAME ROOT :IN,CHAR DEVNAME[39] :IN,FRAME OFFSET :IN,INT SHIFTFRAME :IN)
EXTFCTP FRAME EB_TEST(FRAME ROOT :IN,CHAR DEVICE_NAME[39] :IN,FRAME OFFSET :IN,INT FRAME_NR :IN,BOOL VALID :OUT)
EXTFCTP REAL EO(CHAR DEVICE_NAME[39] :IN,REAL OFFSET :IN)
EXTFCTP INT EMI_ENDPOS(CHAR DEV_NAME[39] :IN,CHAR FILE_NAME[32] :IN,E6POS END_POS :OUT,E6AXIS END_AXIS :OUT)
EXTFCTP INT EMI_STARTPOS(CHAR DEV_NAME[39] :IN,CHAR FILE_NAME[32] :IN,E6POS START_POS :OUT,E6AXIS START_AXIS :OUT)
EXTFCTP INT EMI_ACTPOS(CHAR DEV_NAME[39] :IN,CHAR FILE_NAME[32] :IN,E6POS ACT_POS :OUT,E6AXIS ACT_AXIS :OUT)
EXTFCTP INT EMI_RECSTATE(CHAR DEV_NAME[39] :IN,CHAR FILE_NAME[32] :IN)
EXTFCTP SIGINF GET_SIG_INF(CHAR SIGNAME[24] :IN)
EXTP M_COMMENT (CHAR M_TXT[128] :IN )
Hope this helps anybody as it has helped me.