diff --git a/client.c b/client.c
index e701438..1cd4b37 100644
--- a/client.c
+++ b/client.c
@@ -32,8 +32,10 @@
 #include "socket.h"
 
 static char sendbuf[BUFSIZ];
-// send any message and wait any answer
+// send message and wait any answer
 #define SENDMSG(...) do{snprintf(sendbuf, BUFSIZ-1, __VA_ARGS__); verbose(2, "\t> %s", sendbuf); sendstrmessage(sock, sendbuf); getans(sock, NULL);}while(0)
+// send message and wait answer starting with 'cmd'
+#define SENDMSGW(cmd, ...) do{snprintf(sendbuf, BUFSIZ-1, cmd __VA_ARGS__); verbose(2, "\t> %s", sendbuf); sendstrmessage(sock, sendbuf); getans(sock, cmd);}while(0)
 // send command and wait for answer on it
 #define SENDCMDW(cmd) do{strncpy(sendbuf, cmd, BUFSIZ-1); verbose(2, "\t> %s", sendbuf); sendstrmessage(sock, sendbuf); getans(sock, cmd);}while(0)
 static volatile atomic_int expstate = CAMERA_CAPTURE;
@@ -143,59 +145,63 @@ static void send_headers(int sock){
     if(GP->listdevices) SENDMSG(CMD_FOCLIST);
     if(GP->focdevno > -1) SENDMSG(CMD_FDEVNO "=%d", GP->focdevno);
     if(!isnan(GP->gotopos)){
-        SENDMSG(CMD_FGOTO "=%g", GP->gotopos);
+        SENDMSGW(CMD_FGOTO, "=%g", GP->gotopos);
     }
     // wheel
-    if(GP->listdevices) SENDMSG(CMD_WLIST);
-    if(GP->whldevno > -1) SENDMSG(CMD_WDEVNO "=%d", GP->whldevno);
-    if(GP->setwheel > -1) SENDMSG(CMD_WPOS "=%d", GP->setwheel);
+    if(GP->listdevices) SENDCMDW(CMD_WLIST);
+    if(GP->whldevno > -1) SENDMSGW(CMD_WDEVNO, "=%d", GP->whldevno);
+    if(GP->setwheel > -1) SENDMSGW(CMD_WPOS, "=%d", GP->setwheel);
     DBG("nxt");
     // CCD/CMOS
-    if(GP->X0 > -1 || GP->Y0 > -1 || GP->X1 > -1 || GP->Y1 > -1){ // set format
-        SENDMSG(CMD_FRAMEMAX);
-        SENDMSG(CMD_FRAMEFORMAT);
-        if(GP->X0 < 0) GP->X0 = xc0; // default values
+    if(GP->X0 > INT_MIN || GP->Y0 > INT_MIN || GP->X1 > INT_MIN || GP->Y1 > INT_MIN){ // set format
+        SENDCMDW(CMD_FRAMEMAX);
+        SENDCMDW(CMD_FRAMEFORMAT);
+        // default values
+        if(GP->X0 == INT_MIN) GP->X0 = xc0;
+        if(GP->X1 == INT_MIN) GP->X1 = xc1;
+        if(GP->Y0 == INT_MIN) GP->Y0 = yc0;
+        if(GP->Y1 == INT_MIN) GP->Y1 = yc1;
+        // limiting values
+        if(GP->X0 < 0) GP->X0 = xm0;
         else if(GP->X0 > xm1-1) GP->X0 = xm1-1;
-        if(GP->Y0 < 0) GP->Y0 = yc0;
+        if(GP->Y0 < 0) GP->Y0 = ym0;
         else if(GP->Y0 > ym1-1) GP->Y0 = ym1-1;
-        if(GP->X1 < GP->X0+1) GP->X1 = xc1;
-        else if(GP->X1 > xm1) GP->X1 = xm1;
-        if(GP->Y1 < GP->Y0+1) GP->Y1 = yc1;
-        else if(GP->Y1 > ym1) GP->Y1 = ym1;
+        if(GP->X1 < GP->X0+1 || GP->X1 > xm1) GP->X1 = xm1;
+        if(GP->Y1 < GP->Y0+1 || GP->Y1 > ym1) GP->Y1 = ym1;
         DBG("set format: (%d,%d)x(%d,%d)", GP->X0,GP->X1,GP->Y0,GP->Y1);
-        SENDMSG(CMD_FRAMEFORMAT "=%d,%d,%d,%d", GP->X0, GP->Y0, GP->X1, GP->Y1);
+        SENDMSGW(CMD_FRAMEFORMAT, "=%d,%d,%d,%d", GP->X0, GP->Y0, GP->X1, GP->Y1);
     }
-    if(GP->cancelexpose) SENDMSG(CMD_EXPSTATE "=%d", CAMERA_IDLE);
-    if(GP->listdevices) SENDMSG(CMD_CAMLIST);
-    if(GP->camdevno > -1) SENDMSG(CMD_CAMDEVNO "=%d", GP->camdevno);
-    if(GP->hbin) SENDMSG(CMD_HBIN "=%d", GP->hbin);
-    if(GP->vbin) SENDMSG(CMD_VBIN "=%d", GP->vbin);
-    if(!isnan(GP->temperature)) SENDMSG(CMD_CAMTEMPER "=%g", GP->temperature);
-    if(GP->shtr_cmd > -1) SENDMSG(CMD_SHUTTER "=%d", GP->shtr_cmd);
-    if(GP->confio > -1) SENDMSG(CMD_CONFIO "=%d", GP->confio);
-    if(GP->setio > -1) SENDMSG(CMD_IO "=%d", GP->setio);\
-    if(!isnan(GP->gain)) SENDMSG(CMD_GAIN "=%g", GP->gain);
-    if(!isnan(GP->brightness)) SENDMSG(CMD_BRIGHTNESS "=%g", GP->brightness);
-    if(GP->nflushes > 0) SENDMSG(CMD_NFLUSHES "=%d", GP->nflushes);
+    if(GP->cancelexpose) SENDMSGW(CMD_EXPSTATE, "=%d", CAMERA_IDLE);
+    if(GP->listdevices) SENDCMDW(CMD_CAMLIST);
+    if(GP->camdevno > -1) SENDMSGW(CMD_CAMDEVNO, "=%d", GP->camdevno);
+    if(GP->hbin) SENDMSGW(CMD_HBIN, "=%d", GP->hbin);
+    if(GP->vbin) SENDMSGW(CMD_VBIN, "=%d", GP->vbin);
+    if(!isnan(GP->temperature)) SENDMSGW(CMD_CAMTEMPER, "=%g", GP->temperature);
+    if(GP->shtr_cmd > -1) SENDMSGW(CMD_SHUTTER, "=%d", GP->shtr_cmd);
+    if(GP->confio > -1) SENDMSGW(CMD_CONFIO, "=%d", GP->confio);
+    if(GP->setio > -1) SENDMSGW(CMD_IO, "=%d", GP->setio);\
+    if(!isnan(GP->gain)) SENDMSGW(CMD_GAIN, "=%g", GP->gain);
+    if(!isnan(GP->brightness)) SENDMSGW(CMD_BRIGHTNESS, "=%g", GP->brightness);
+    if(GP->nflushes > 0) SENDMSGW(CMD_NFLUSHES, "=%d", GP->nflushes);
     if(GP->outfile || GP->outfileprefix){ // exposition and reading control: only if start of exposition
-        if(GP->_8bit) SENDMSG(CMD_8BIT "=1");
-        else SENDMSG(CMD_8BIT "=0");
-        if(GP->fast) SENDMSG(CMD_FASTSPD "=1");
-        else SENDMSG(CMD_FASTSPD "=0");
-        if(GP->dark) SENDMSG(CMD_DARK "=1");
-        else SENDMSG(CMD_DARK "=0");
+        if(GP->_8bit) SENDMSGW(CMD_8BIT, "=1");
+        else SENDMSGW(CMD_8BIT, "=0");
+        if(GP->fast) SENDMSGW(CMD_FASTSPD, "=1");
+        else SENDMSGW(CMD_FASTSPD, "=0");
+        if(GP->dark) SENDMSGW(CMD_DARK, "=1");
+        else SENDMSGW(CMD_DARK, "=0");
     }
     if(GP->outfile){
-        if(!*GP->outfile) SENDMSG(CMD_FILENAME "=");
-        else SENDMSG(CMD_FILENAME "=%s", makeabspath(GP->outfile, FALSE));
-        if(GP->rewrite) SENDMSG(CMD_REWRITE "=1");
-        else SENDMSG(CMD_REWRITE "=0");
+        if(!*GP->outfile) SENDMSGW(CMD_FILENAME, "=");
+        else SENDMSGW(CMD_FILENAME, "=%s", makeabspath(GP->outfile, FALSE));
+        if(GP->rewrite) SENDMSGW(CMD_REWRITE, "=1");
+        else SENDMSGW(CMD_REWRITE, "=0");
     }
     if(GP->outfileprefix){
-        if(!*GP->outfileprefix) SENDMSG(CMD_FILENAMEPREFIX "=");
-        else SENDMSG(CMD_FILENAMEPREFIX "=%s", makeabspath(GP->outfileprefix, FALSE));
+        if(!*GP->outfileprefix) SENDMSGW(CMD_FILENAMEPREFIX, "=");
+        else SENDMSGW(CMD_FILENAMEPREFIX, "=%s", makeabspath(GP->outfileprefix, FALSE));
     }
-    if(GP->exptime > -DBL_EPSILON) SENDMSG(CMD_EXPOSITION "=%g", GP->exptime);
+    if(GP->exptime > -DBL_EPSILON) SENDMSGW(CMD_EXPOSITION, "=%g", GP->exptime);
     // FITS header keywords:
 #define CHKHDR(x, cmd)   do{if(x) SENDMSG(cmd "=%s", x);}while(0)
     CHKHDR(GP->author, CMD_AUTHOR);
@@ -216,13 +222,13 @@ static void send_headers(int sock){
             int N = snprintf(ptr, L-1, "%s,", *sptr++);
             L -= N; ptr += N;
         }
-        SENDMSG(CMD_HEADERFILES "=%s", buf);
+        SENDMSGW(CMD_HEADERFILES, "=%s", buf);
     }
 }
 
 void client(int sock){
     if(GP->restart){
-        SENDMSG(CMD_RESTART);
+        SENDCMDW(CMD_RESTART);
         return;
     }
     send_headers(sock);
@@ -233,7 +239,7 @@ void client(int sock){
         Nremain = GP->nframes - 1;
         if(Nremain < 1) Nremain = 0;
         else GP->waitexpend = TRUE; // N>1 - wait for exp ends
-        SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE);
+        SENDMSGW(CMD_EXPSTATE, "=%d", CAMERA_CAPTURE);
     }else{
         getans(sock, NULL);
         DBG("RETURN: no more data");
@@ -247,7 +253,7 @@ void client(int sock){
     }
     while(dtime() - t0 < timeout){
         if(GP->waitexpend && dtime() - tw > WAIT_TIMEOUT){
-            SENDMSG(CMD_TREMAIN); // get remained time
+            SENDCMDW(CMD_TREMAIN); // get remained time
             tw = dtime();
             sprintf(sendbuf, "%s", CMD_EXPSTATE);
             sendstrmessage(sock, sendbuf);
@@ -266,7 +272,7 @@ void client(int sock){
                     if(GP->pause_len > 0){
                         double delta, time1 = dtime() + GP->pause_len;
                         while(1){
-                            SENDMSG(CMD_CAMTEMPER);
+                            SENDCMDW(CMD_CAMTEMPER);
                             if((delta = time1 - dtime()) < __FLT_EPSILON__) break;
                             // %d секунд до окончания паузы\n
                             if(delta > 1.) verbose(1, _("%d seconds till pause ends\n"), (int)delta);
@@ -277,7 +283,7 @@ void client(int sock){
                     }
                     verbose(1, "Exposing frame %d...", ++nframe);
                     --Nremain;
-                    SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE);
+                    SENDMSGW(CMD_EXPSTATE, "=%d", CAMERA_CAPTURE);
                 }else{
                     GP->waitexpend = 0;
                     timeout = WAIT_TIMEOUT; // wait for last file name
@@ -301,8 +307,8 @@ static void getimage(){
     FNAME();
     int sock = controlfd;
     TIMESTAMP("Get image sizes");
-    SENDMSG(CMD_IMWIDTH);
-    SENDMSG(CMD_IMHEIGHT);
+    SENDCMDW(CMD_IMWIDTH);
+    SENDCMDW(CMD_IMHEIGHT);
     int imsock = open_socket(FALSE, GP->imageport, TRUE);
     if(imsock < 0) ERRX("getimage(): can't open image transport socket");
     if(imbufsz < imdatalen){
@@ -342,7 +348,7 @@ static void *grabnext(void _U_ *arg){ // daemon grabbing images through the net
         expstate = CAMERA_CAPTURE;
         TIMESTAMP("End of cycle, start new #%d", grabno+1);
         TIMEINIT();
-        SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE); // start capture
+        SENDMSGW(CMD_EXPSTATE, "=%d", CAMERA_CAPTURE); // start capture
         double timeout = GP->exptime + CLIENT_TIMEOUT, t0 = dtime();
         useconds_t sleept = 500000; // 0.5s
         if(GP->exptime < 0.5){
diff --git a/cmdlnopts.c b/cmdlnopts.c
index 24a4b5f..21e704f 100644
--- a/cmdlnopts.c
+++ b/cmdlnopts.c
@@ -18,8 +18,8 @@ static glob_pars  G = {
     .instrument = NULL,
     .exptime = -1.,
     .nframes = 0,
-    .X0 = -1, .Y0 = -1,
-    .X1 = -1, .Y1 = -1,
+    .X0 = INT_MIN, .Y0 = INT_MIN,
+    .X1 = INT_MIN, .Y1 = INT_MIN,
     .focdevno = -1,
     .camdevno = -1,
     .whldevno = -1,
diff --git a/locale/ru/messages.po b/locale/ru/messages.po
index 4baf3f3..3648bda 100644
--- a/locale/ru/messages.po
+++ b/locale/ru/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2023-04-11 10:00+0300\n"
+"POT-Creation-Date: 2023-04-11 14:57+0300\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -478,12 +478,12 @@ msgstr ""
 msgid "Can't set brightness to %g"
 msgstr ""
 
-#: ccdfunc.c:725 server.c:236
+#: ccdfunc.c:725 server.c:251
 #, c-format
 msgid "Can't set binning %dx%d"
 msgstr ""
 
-#: ccdfunc.c:737 server.c:237
+#: ccdfunc.c:737 server.c:252
 msgid "Can't set given geometry"
 msgstr ""
 
@@ -529,7 +529,7 @@ msgstr ""
 msgid "Capture frame %d"
 msgstr ""
 
-#: ccdfunc.c:783 ccdfunc.c:857 server.c:122
+#: ccdfunc.c:783 ccdfunc.c:857 server.c:137
 msgid "Can't start exposition"
 msgstr ""
 
@@ -546,7 +546,7 @@ msgid "Can't grab image"
 msgstr ""
 
 #. %d я│п╣п╨я┐п╫п╢ п╢п╬ п╬п╨п╬п╫я┤п╟п╫п╦я▐ п©п╟я┐п╥я▀\n
-#: ccdfunc.c:807 client.c:272
+#: ccdfunc.c:807 client.c:278
 #, c-format
 msgid "%d seconds till pause ends\n"
 msgstr ""
@@ -555,15 +555,15 @@ msgstr ""
 msgid "Some error when capture"
 msgstr ""
 
-#: server.c:170
+#: server.c:185
 msgid "No camera device"
 msgstr ""
 
-#: client.c:259
+#: client.c:265
 msgid "Can't make exposition"
 msgstr ""
 
-#: client.c:288
+#: client.c:294
 msgid "Server timeout"
 msgstr ""
 
diff --git a/locale/ru/ru.po b/locale/ru/ru.po
index 6590d3a..e7adef0 100644
--- a/locale/ru/ru.po
+++ b/locale/ru/ru.po
@@ -7,7 +7,7 @@
 msgid   ""
 msgstr  "Project-Id-Version: PACKAGE VERSION\n"
         "Report-Msgid-Bugs-To: \n"
-        "POT-Creation-Date: 2023-04-11 09:57+0300\n"
+        "POT-Creation-Date: 2023-04-11 14:24+0300\n"
         "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
         "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
         "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -22,7 +22,7 @@ msgid   "%.1f seconds till exposition ends"
 msgstr  "%.1f секунд до окончания экспозиции"
 
 #. %d я│п╣п╨я┐п╫п╢ п╢п╬ п╬п╨п╬п╫я┤п╟п╫п╦я▐ п©п╟я┐п╥я▀\n
-#: ccdfunc.c:807 client.c:272
+#: ccdfunc.c:807 client.c:278
 #, c-format
 msgid   "%d seconds till pause ends\n"
 msgstr  "%d секунд до окончания паузы\n"
@@ -117,7 +117,7 @@ msgstr  "
 msgid   "Can't init mutex!"
 msgstr  "Не могу инициализировать мьютекс!"
 
-#: client.c:259
+#: client.c:265
 msgid   "Can't make exposition"
 msgstr  "Не могу выполнить экспозицию"
 
@@ -162,7 +162,7 @@ msgstr  "
 msgid   "Can't set active wheel number"
 msgstr  "Не могу установить номер активного колеса"
 
-#: ccdfunc.c:725 server.c:236
+#: ccdfunc.c:725 server.c:251
 #, c-format
 msgid   "Can't set binning %dx%d"
 msgstr  "Не могу установить биннинг %dx%d"
@@ -190,7 +190,7 @@ msgstr  "
 msgid   "Can't set gain to %g"
 msgstr  "Не могу установить Gain в %g"
 
-#: ccdfunc.c:737 server.c:237
+#: ccdfunc.c:737 server.c:252
 msgid   "Can't set given geometry"
 msgstr  "Не могу установить геометрию"
 
@@ -213,7 +213,7 @@ msgstr  "
 msgid   "Can't set wheel position %d"
 msgstr  "Не могу установить положение колеса %d"
 
-#: ccdfunc.c:783 ccdfunc.c:857 server.c:122
+#: ccdfunc.c:783 ccdfunc.c:857 server.c:137
 msgid   "Can't start exposition"
 msgstr  "Не могу начать экспозицию"
 
@@ -289,7 +289,7 @@ msgstr  "
 msgid   "N flushes before exposing (default: 1)"
 msgstr  "N засвечиваний перед экспозицией (по умолчанию: 1)"
 
-#: server.c:170
+#: server.c:185
 msgid   "No camera device"
 msgstr  "Не указано устройство камеры"
 
@@ -323,7 +323,7 @@ msgstr  "
 msgid   "Readout mode: %s"
 msgstr  "Режим считывания: %s"
 
-#: client.c:288
+#: client.c:294
 msgid   "Server timeout"
 msgstr  "Таймаут сервера"
 
diff --git a/server.c b/server.c
index 865aac2..09df7a2 100644
--- a/server.c
+++ b/server.c
@@ -30,6 +30,8 @@
 #include "server.h"
 #include "socket.h"
 
+static int processData(int fd, handleritem *handlers, char *buf, int buflen);
+
 static atomic_int camdevno = 0, wheeldevno = 0, focdevno = 0; // current devices numbers
 static _Atomic camera_state camstate = CAMERA_IDLE;
 #define FLAG_STARTCAPTURE       (1<<0)
@@ -37,7 +39,6 @@ static _Atomic camera_state camstate = CAMERA_IDLE;
 #define FLAG_RESTARTSERVER      (1<<2)
 static atomic_int camflags = 0, camfanspd = 0, confio = 0, nflushes;
 static char *outfile = NULL, *lastfile = NULL; // current output file name/prefix; last name of saved file
-//static pthread_mutex_t locmutex = PTHREAD_MUTEX_INITIALIZER; // mutex for wheel/camera/focuser functions
 static frameformat frmformatmax = {0}, curformat = {0}; // maximal format
 static void *camdev = NULL, *focdev = NULL, *wheeldev = NULL;
 
@@ -97,6 +98,20 @@ strpair allcommands[] = {
     {NULL, NULL},
 };
 
+static pthread_mutex_t locmutex = PTHREAD_MUTEX_INITIALIZER; // mutex for wheel/camera/focuser functions
+
+// return TRUE if `locmutex` can be locked
+static int lock(){
+    if(pthread_mutex_trylock(&locmutex)){
+        DBG("\n\nAlready locked");
+        return FALSE;
+    }
+    return TRUE;
+}
+static void unlock(){
+    if(pthread_mutex_unlock(&locmutex)) ERR("Can't unlock mutex");
+}
+
 static IMG ima = {0};
 static void fixima(){
     FNAME();
@@ -176,7 +191,7 @@ static void* processCAM(_U_ void *d){
             signals(1);
         }
         usleep(100);
-        if(0 == pthread_mutex_trylock(&locmutex)){
+        if(lock()){
             // log
             if(dtime() - logt > TLOG_PAUSE){
                 logt = dtime();
@@ -206,7 +221,7 @@ static void* processCAM(_U_ void *d){
     // do nothing: when `server` got this state it sends "expstate=3" to all clients and changes state to IDLE
                 break;
             }
-            pthread_mutex_unlock(&locmutex);
+            unlock();
         }
     }
     return NULL;
@@ -354,7 +369,6 @@ static hresult nameprefixhandler(_U_ int fd, _U_ const char *key, const char *va
         char *path = makeabspath(val, FALSE);
         if(!path){
             LOGERR("Can't create file '%s'", val);
-            //pthread_mutex_unlock(&locmutex);
             return RESULT_BADVAL;
         }
         FREE(outfile);
@@ -676,7 +690,6 @@ static hresult FITSheaderhandler(int fd, _U_ const char *key, const char *val){
                     FREE(*sptr++);
                 }
                 FREE(list);
-                //pthread_mutex_unlock(&locmutex);
                 return RESULT_BADVAL;
             }
             *lptr++ = strdup(newpath);
@@ -958,8 +971,8 @@ static handleritem items[] = {
     {chkcc,  formathandler, CMD_FRAMEMAX},
     {chkcc,  nflusheshandler, CMD_NFLUSHES},
     {chkcam, expstatehandler, CMD_EXPSTATE},
-    {NULL,   imsizehandler, CMD_IMWIDTH},
-    {NULL,   imsizehandler, CMD_IMHEIGHT},
+    {chktrue,imsizehandler, CMD_IMWIDTH},
+    {chktrue,imsizehandler, CMD_IMHEIGHT},
     {chkcc,  nameprefixhandler, CMD_FILENAMEPREFIX},
     {chkcc,  rewritefilehandler, CMD_REWRITE},
     {chkcc,  _8bithandler, CMD_8BIT},
@@ -1125,3 +1138,77 @@ char *makeabspath(const char *path, int shouldbe){
     if(unl) unlink(path);
     return ret;
 }
+
+// parse string of data (command or key=val)
+// the CONTENT of buffer `str` WILL BE BROKEN!
+// @return FALSE if client closed (nothing to read)
+static int parsestring(int fd, handleritem *handlers, char *str){
+    if(fd < 1 || !handlers || !handlers->key || !str || !*str) return FALSE;
+    char *val = get_keyval(str);
+    if(val){
+        DBG("RECEIVE '%s=%s'", str, val);
+        LOGDBG("RECEIVE '%s=%s'", str, val);
+    }else{
+        DBG("RECEIVE '%s'", str);
+        LOGDBG("RECEIVE '%s'", str);
+    }
+    for(handleritem *h = handlers; h->key; ++h){
+        if(strcmp(str, h->key) == 0){ // found command
+            hresult r = RESULT_OK;
+            int l = FALSE;
+            if(h->chkfunction){
+                double t0 = dtime();
+                do{ l = lock(); } while(!l && dtime() - t0 < BUSY_TIMEOUT);
+                DBG("time: %g", dtime() - t0);
+                if(!l){
+                    WARN("Can't lock mutex"); //signals(1);
+                    return RESULT_BUSY; // long blocking work
+                }
+                r = h->chkfunction(val);
+            } // else NULL instead of chkfuntion -> don't check and don't lock mutex
+            if(r == RESULT_OK){ // no test function or it returns TRUE
+                if(h->handler) r = h->handler(fd, str, val);
+                else r = RESULT_FAIL;
+            }
+            if(l) unlock();
+            if(r == RESULT_DISCONNECTED){
+                DBG("handler return RESULT_DISCONNECTED");
+                return FALSE;
+            }
+            return sendstrmessage(fd, hresult2str(r));
+        }
+    }
+    DBG("Command not found!");
+    return sendstrmessage(fd, hresult2str(RESULT_BADKEY));
+}
+
+/**
+ * @brief processData - read (if available) data from fd and run processing, sending to fd messages for each command
+ * @param fd        - socket file descriptor
+ * @param handlers  - NULL-terminated array of handlers
+ * @param buf (io)   - zero-terminated buffer for storing rest of data (without newline), its content will be changed
+ * @param buflen    - its length
+ * @return FALSE if client closed (nothing to read)
+ */
+static int processData(int fd, handleritem *handlers, char *buf, int buflen){
+    int curlen = strlen(buf);
+    if(curlen == buflen-1) curlen = 0; // buffer overflow - clear old content
+    ssize_t rd = read(fd, buf + curlen, buflen-1 - curlen);
+    if(rd <= 0){
+        //DBG("read %zd bytes from client", rd);
+        return FALSE;
+    }
+    //DBG("got %s[%zd] from %d", buf, rd, fd);
+    char *restofdata = buf, *eptr = buf + curlen + rd;
+    *eptr = 0;
+    do{
+        char *nl = strchr(restofdata, '\n');
+        if(!nl) break;
+        *nl++ = 0;
+        if(!parsestring(fd, handlers, restofdata)) return FALSE; // client disconnected
+        restofdata = nl;
+        //DBG("rest of data: %s", restofdata);
+    }while(1);
+    if(restofdata != buf) memmove(buf, restofdata, eptr - restofdata + 1);
+    return TRUE;
+}
diff --git a/socket.c b/socket.c
index 14ed413..c4da21a 100644
--- a/socket.c
+++ b/socket.c
@@ -38,8 +38,6 @@
 double __t0 = 0.;
 #endif
 
-pthread_mutex_t locmutex = PTHREAD_MUTEX_INITIALIZER; // mutex for wheel/camera/focuser functions
-
 /**
  * @brief open_socket - create socket and open it
  * @param isserver  - TRUE for server, FALSE for client
@@ -187,7 +185,7 @@ int sendmessage(int fd, const char *msg, int l){
         buflen += 1024;
         tmpbuf = realloc(tmpbuf, buflen);
     }
-    //DBG("send to fd %d: %s [%d]", fd, msg, l);
+    DBG("send to fd %d: %s [%d]", fd, msg, l);
     memcpy(tmpbuf, msg, l);
     if(msg[l-1] != '\n') tmpbuf[l++] = '\n';
     if(l != send(fd, tmpbuf, l, MSG_NOSIGNAL)){
@@ -248,79 +246,6 @@ char *get_keyval(char *keyval){
     return val;
 }
 
-// parse string of data (command or key=val)
-// the CONTENT of buffer `str` WILL BE BROKEN!
-// @return FALSE if client closed (nothing to read)
-static int parsestring(int fd, handleritem *handlers, char *str){
-    if(fd < 1 || !handlers || !handlers->key || !str || !*str) return FALSE;
-    char *val = get_keyval(str);
-    if(val){
-        DBG("RECEIVE '%s=%s'", str, val);
-        LOGDBG("RECEIVE '%s=%s'", str, val);
-    }else{
-        DBG("RECEIVE '%s'", str);
-        LOGDBG("RECEIVE '%s'", str);
-    }
-    for(handleritem *h = handlers; h->key; ++h){
-        if(strcmp(str, h->key) == 0){ // found command
-            hresult r = RESULT_OK;
-            int l = 1;
-            if(h->chkfunction){
-                double t0 = dtime();
-                do{ l = pthread_mutex_trylock(&locmutex); }while(l && dtime() - t0 > BUSY_TIMEOUT);
-                if(l){
-                    DBG("Can't lock mutex");
-                    return RESULT_BUSY; // long blocking work
-                }
-                r = h->chkfunction(val);
-            } // else NULL instead of chkfuntion -> don't check and don't lock mutex
-            if(r == RESULT_OK){ // no test function or it returns TRUE
-                if(h->handler) r = h->handler(fd, str, val);
-                else r = RESULT_FAIL;
-            }
-            if(!l) pthread_mutex_unlock(&locmutex);
-            if(r == RESULT_DISCONNECTED){
-                DBG("handler return RESULT_DISCONNECTED");
-                return FALSE;
-            }
-            return sendstrmessage(fd, hresult2str(r));
-        }
-    }
-    DBG("Command not found!");
-    return sendstrmessage(fd, resmessages[RESULT_BADKEY]);
-}
-
-/**
- * @brief processData - read (if available) data from fd and run processing, sending to fd messages for each command
- * @param fd        - socket file descriptor
- * @param handlers  - NULL-terminated array of handlers
- * @param buf (io)   - zero-terminated buffer for storing rest of data (without newline), its content will be changed
- * @param buflen    - its length
- * @return FALSE if client closed (nothing to read)
- */
-int processData(int fd, handleritem *handlers, char *buf, int buflen){
-    int curlen = strlen(buf);
-    if(curlen == buflen-1) curlen = 0; // buffer overflow - clear old content
-    ssize_t rd = read(fd, buf + curlen, buflen-1 - curlen);
-    if(rd <= 0){
-        //DBG("read %zd bytes from client", rd);
-        return FALSE;
-    }
-    //DBG("got %s[%zd] from %d", buf, rd, fd);
-    char *restofdata = buf, *eptr = buf + curlen + rd;
-    *eptr = 0;
-    do{
-        char *nl = strchr(restofdata, '\n');
-        if(!nl) break;
-        *nl++ = 0;
-        if(!parsestring(fd, handlers, restofdata)) return FALSE; // client disconnected
-        restofdata = nl;
-        //DBG("rest of data: %s", restofdata);
-    }while(1);
-    if(restofdata != buf) memmove(buf, restofdata, eptr - restofdata + 1);
-    return TRUE;
-}
-
 /**
  * check data from  fd (polling function for client)
  * @param fd - file descriptor
diff --git a/socket.h b/socket.h
index 805ebaf..f0bc744 100644
--- a/socket.h
+++ b/socket.h
@@ -30,7 +30,7 @@
 #define MAXCLIENTS  (30)
 
 // wait for mutex locking
-#define BUSY_TIMEOUT    (0.1)
+#define BUSY_TIMEOUT    (1.0)
 // waiting for answer timeout
 #define ANSWER_TIMEOUT  (1.0)
 // wait for exposition ends (between subsequent check calls)
@@ -47,16 +47,14 @@ extern double __t0;
 #define TIMESTAMP(...)
 #endif
 
-extern pthread_mutex_t locmutex;
-
 typedef enum{
-    RESULT_OK,      // all OK
-    RESULT_BUSY,    // camera busy and no setters can be done
-    RESULT_FAIL,    // failed running command
-    RESULT_BADVAL,  // bad key's value
-    RESULT_BADKEY,  // bad key
-    RESULT_SILENCE, // send nothing to client
-    RESULT_DISCONNECTED,// client disconnected
+    RESULT_OK,          // 0: all OK
+    RESULT_BUSY,        // 1: camera busy and no setters can be done
+    RESULT_FAIL,        // 2: failed running command
+    RESULT_BADVAL,      // 3: bad key's value
+    RESULT_BADKEY,      // 4: bad key
+    RESULT_SILENCE,     // 5: send nothing to client
+    RESULT_DISCONNECTED,// 6: client disconnected
     RESULT_NUM
 } hresult;
 
@@ -78,5 +76,4 @@ int sendmessage(int fd, const char *msg, int l);
 int sendstrmessage(int fd, const char *msg);
 char *get_keyval(char *keyval);
 
-int processData(int fd, handleritem *handlers, char *buf, int buflen);
 int canberead(int fd);