Change extrapolation log messages strategy

Change the log strategy regarding extrapolation from
make a message every time, to show the maximum number of
extrapolation steps observed in a row and the current count

In this way the log will not be filled up with identical messages,
hiding other messages.

Valuable when running on an unstable network like WIFI

ur_rtde_driver/resources/servoj.urscript

@@ -1,16 +1,22 @@
 {{BEGIN_REPLACE}}
 
-global steptime = get_steptime()
+steptime = get_steptime()
 textmsg("steptime=", steptime)
-global MULT_jointstate = {{JOINT_STATE_REPLACE}}
+MULT_jointstate = {{JOINT_STATE_REPLACE}}
 
-global SERVO_STOPPED = -2
-global SERVO_UNINITIALIZED = -1
-global SERVO_IDLE = 0
-global SERVO_RUNNING = 1
+#Constants
+SERVO_STOPPED = -2
+SERVO_UNINITIALIZED = -1
+SERVO_IDLE = 0
+SERVO_RUNNING = 1
+
+#Global variables are also showed in the Teach pendants variable list
 global cmd_servo_state = SERVO_UNINITIALIZED
 global cmd_servo_q = get_actual_joint_positions()
 global cmd_servo_q_last = get_actual_joint_positions()
+global extrapolate_count = 0
+global extrapolate_max_count = 0
+
 def set_servo_setpoint(q):
   cmd_servo_state = SERVO_RUNNING
   cmd_servo_q_last = cmd_servo_q
@@ -38,13 +44,22 @@ thread servoThread():
     if cmd_servo_state > SERVO_UNINITIALIZED:
       cmd_servo_state = SERVO_IDLE
     end
+
     if do_extrapolate:
-      textmsg("No new setpoint received. Extrapolating.")
+      extrapolate_count = extrapolate_count + 1
+      if extrapolate_count > extrapolate_max_count:
+        extrapolate_max_count = extrapolate_count
+      end
+
       q = extrapolate()
       servoj(q, t=steptime, {{SERVO_J_REPLACE}})
+
     elif state == SERVO_RUNNING:
+      extrapolate_count = 0
       servoj(q, t=steptime, {{SERVO_J_REPLACE}})
+
     else:
+      extrapolate_count = 0
       sync()
     end
     exit_critical
@@ -71,6 +86,7 @@ while keepalive > 0:
   end
   exit_critical
 end
+
 textmsg("Stopping communication and servoing")
 cmd_servo_state = SERVO_STOPPED
 sleep(.1)