motion.c: Improve handling of misc_error pin names

See #2780
And #2773
Also document the use of names_misc_errors

Author: andypugh

docs/man/man9/motion.9

@@ -4,7 +4,7 @@
 motion \- accepts NML motion commands, interacts with HAL in realtime
 
 .SH SYNOPSIS
-\fBloadrt motmod [base_period_nsec=\fIperiod\fB] [base_thread_fp=\fI0 or 1\fB] [servo_period_nsec=\fIperiod\fB] [traj_period_nsec=\fIperiod\fB] [num_joints=\fI[1-16]\fB] [num_dio=\fI[1-64]\fB] [num_aio=\fI[1-64]\fB] [num_misc_error=\fI[0-64]\fB] [num_spindles=\fI[1-8]\fB]\fR  \fB[unlock_joints_mask=\fR\fIjointmask\fR\fB]\fR \fB[num_extrajoints=\fI[0-16]\fB]\fR
+\fBloadrt motmod [base_period_nsec=\fIperiod\fB] [base_thread_fp=\fI0 or 1\fB] [servo_period_nsec=\fIperiod\fB] [traj_period_nsec=\fIperiod\fB] [num_joints=\fI[1-16]\fB] [num_dio=\fI[1-64]\fB] [num_aio=\fI[1-64]\fB] [num_misc_error=\fI[0-64]\fB | names_misc_errors] [num_spindles=\fI[1-8]\fB]\fR  \fB[unlock_joints_mask=\fR\fIjointmask\fR\fB]\fR \fB[num_extrajoints=\fI[0-16]\fB]\fR
 
 The limits for the following items are compile-time settings:
 .br
@@ -26,6 +26,13 @@ The limits for the following items are compile-time settings:
 .br
 .ns
 .TP
+\fBnames_misc_errors\fR: A comma-separated list of names for extra error inputs.
+This parameter is mutually exclusive with num_misc_error.
+If using num_misc_error the additional error input pins will have names like \fBmotion.misc-error-00\fR whereas \fBnames_misc_errors=overtemp,undertemp\fR will
+create hal pins \fBmotion.err-overtemp\fR and \fBmotion.err-undertemp\fR
+.br
+.ns
+.TP
 \fBnum_spindles\fR: Maximum number of spindles is set by EMCMOT_MAX_SPINDLES
 
 .P

src/emc/motion/motion.c

@@ -72,7 +72,7 @@ static char *names_ain[MAX_IO] = {0,};
 RTAPI_MP_ARRAY_STRING(names_ain, MAX_IO, "names of analog inputs");
 static char *names_aout[MAX_IO] = {0,};
 RTAPI_MP_ARRAY_STRING(names_aout, MAX_IO, "names of analog outputs");
-static int num_misc_error = DEFAULT_MISC_ERROR;	/* default number of misc errors */
+static int num_misc_error = -1;   /* To check use of num_misc_error modparam */
 RTAPI_MP_INT(num_misc_error, "number of misc error inputs");
 
 static char *names_misc_errors[MAX_IO] = {0,};
@@ -341,15 +341,14 @@ int rtapi_app_main(void)
 	return -1;
     }
 
-  if(num_misc_error && (names_misc_errors[0])){
+  if(num_misc_error != -1 && (names_misc_errors[0])){
     rtapi_print_msg(RTAPI_MSG_ERR, _("MOTION: Can't specify both names and number for misc error\n"));
     return -1;
   }
   else if(names_misc_errors[0]){
-    num_misc_error = count_names(names_dout);
-    num_misc_error = (num_misc_error > count_names(names_din)) ? num_misc_error : count_names(names_din);
+    num_misc_error = count_names(names_misc_errors);
   }
-  else if(!num_misc_error){
+  else {
     num_misc_error = DEFAULT_MISC_ERROR;
   }