diff --git a/daq b/daq
old mode 100644
new mode 100755
index c567bad..6812fbc
Binary files a/daq and b/daq differ
diff --git a/daq.c b/daq.c
index fdc0654..472072f 100644
--- a/daq.c
+++ b/daq.c
@@ -33,8 +33,12 @@ int str2int(unsigned char *ptr);
 int DAQ(int t_hrs, int tm_s);
 
 
-int main(){
+int main(int argc, int argT, int argt){
     
+    if(argc!=3){
+    printf("Invalid number of arguments,\n usage: daq <time(h)> <sampling period(s)>\nexiting!\n");
+    return -2;
+    }
     //configuración de sensores
     printf("Configuring CO2 sensor\n");
     sensConf(GC0017, B9600, Pulling_Mode, " K 00002\r\n");
@@ -46,7 +50,7 @@ int main(){
     
     //adquisición
     printf("Starting data acquisition\n");
-    DAQ(1, 3);
+    DAQ(argT, argt);
     sleep(1);
     
     //finalización