#44 refactor for MODBUS-RTU client features

MBBASE

@@ -0,0 +1,58 @@
+\ STM8EF-MODBUS Base words for server and client
+
+#require UARTISR
+#require CRC16
+
+NVM
+  VARIABLE mbp 2 ALLOT  \ MODBUS parameter 1 and 2
+
+  \ 1st MODBUS FC parameter
+  : mbp1 ( -- n )
+    mbp @
+  ;
+
+  \ 2nd MODBUS FC parameter
+  : mbp2 ( -- n )
+    mbp 2+ @
+  ;
+
+  \ MODBUS write response (e.g FC05, FC06, FC15, FC16)
+  : MBWR  ( -- )
+    mbp1 tx+ mbp2 tx+  \ copy 1st and 2nd parameter
+  ;
+
+  \ MB loop (xt) from mbp1 to mbp1+mbp2
+  : mbloop ( xt -- )
+    mbp1 mbp2 OVER + SWAP  DO
+      ( xt ) I OVER EXECUTE
+    LOOP
+    ( xt ) DROP
+  ;
+
+  \ MB looped bit read with action xt, build response (FC01, FC02, FC03, FC04)
+  : mbread ( xt bpu -- )
+    ( xt bpu ) DUP mbp2 * ( bpu bits )
+    \ N* as quantity of bits / 8, if the remainder is different of 0 => N=N+1
+    ( bits ) 1- 8 / 1+ ( N* ) DUP txc+
+    ( bpu N* ) SWAP ( bpu ) 1 = IF
+       ( N* ) 1- FOR 0 txc+ NEXT  \ init bytes in response with 0
+    ELSE
+       ( N* ) DROP  \ not a bitfield, no memory init
+    THEN
+    ( xt ) mbloop
+  ;
+
+  \ execute xt if not 0
+  : @?EXEC ( a -- ) @ ?DUP IF
+    ( xt ) EXECUTE
+    THEN
+  ;
+
+  \ calc CRC16 from buffer a0 to a1
+  : MBCRC ( a1 a0 -- crc-le )
+    -1 ROT ROT ( -1 a1 a0 ) DO
+      I C@ CRC16
+    LOOP
+    ( CRC16 ) EXG ( CRC-LE )
+  ;
+RAM

MBCLIENT

@@ -0,0 +1,63 @@
+\ STM8 eForth MODBUS basic client routines
+
+#require MBUTILS
+
+NVM
+  VARIABLE clrec   \ XT for client receive handler
+  VARIABLE clerr   \ XT for client error handler
+  VARIABLE clnfc   \ requested MODBUS Node ID and FC
+  VARIABLE crcerr  \ CRC error counter
+
+  \ MODBUS protocol handler
+  : CLPROTO ( -- )
+    rtbuf rxp @ - ( rx )        \ data has been received
+    1 TIM tstamp @ - < ( gap )  \ gap signals message complete
+    ( rx gap ) AND IF 
+      rxp @ 2- ( a1 ) DUP rtbuf ( a1 a1 a0 )
+      MBCRC ( a1 crc-le ) SWAP @ = ( crc-OK ) IF
+        rtbuf @ clnfc @ = IF    \ node address abd FC match
+           clrec @?EXEC
+        ELSE
+           clerr @?EXEC
+        THEN
+      ELSE
+        1 crcerr +!
+      THEN
+      rxres
+    THEN
+  ;
+
+RAM
+
+\ Example
+
+\ Minimal MODBUS client with a FC06 "Write Single Register" handler
+
+#require CLPROTO
+
+RAM
+#require WIPE
+
+#require 'IDLE
+
+NVM
+#require MBDUMP
+  : tst ( -- )
+    txres
+    1 256 *  ( node )  3 ( fc ) +
+    DUP rtbuf ! clnfc ! 
+
+    $EA60 tx+  $0005 tx+
+
+    tbp @ rtbuf ( a1 a0 ) MBCRC ( CRC-LE ) tx+
+    send
+  ;
+
+  : init ( -- )
+    0 UARTISR                     \ init UART handler w/ default baud rate
+    [ ' MBDUMP ] LITERAL clrec !  \ MB Client receive action
+    [ ' CLPROTO ] LITERAL 'IDLE ! \ run MB Client protocol handler as idle task
+  ;
+
+  ' init 'BOOT !
+WIPE RAM

MBPROTO

@@ -1,32 +1,28 @@
 \ STM8 eForth MODBUS protocol handler - intended to run as an IDLE task
 
-#require UARTISR
-#require CRC16
+#require MBBASE
 #require ]B!
-#require WIPE
 
 NVM
   VARIABLE mbnode  \ MODBUS node id
   VARIABLE crcerr  \ CRC error counter
   VARIABLE mbpre   \ xt for FC preparation (e.g. reading inputs)
   VARIABLE mbact   \ xt for output action (e.g. output, debugging)
   VARIABLE mbdef   \ xt for default handler
-  VARIABLE mbp 2 ALLOT  \ MODBUS parameter 1 and 2
-
-  \ calc CRC16 from buffer a0 to a1
-  : MBCRC ( a1 a0 -- crc-le )
-    -1 ROT ROT ( -1 a1 a0 ) DO
-      I C@ CRC16
-    LOOP
-    ( CRC16 ) EXG ( CRC-LE )
-  ;
 
   \ flag MODBUS Exception and set code
   : MBEC ( ec -- )
     [ 1 rtbuf 1+ 7 ]B!  \ flag error in FC field
     ( ec ) txc+         \ and put EC
   ;
 
+  \ true if n in range mbp1,mbp2, else false and MODBUS EC=2
+  : mbrange? ( n -- b )
+    -1 ( b ) SWAP mbp1 mbp2 + - 0< IF
+      2 MBEC ( b ) NOT
+    THEN
+  ;
+
   \ default FC handler - raise EC 1 "ILLEGAL FUNCTION"
   : FCDEF ( -- )
     mbdef @ ?DUP IF
@@ -49,60 +45,11 @@ NVM
     2* ( [ tab ] ) LITERAL +
   ;
 
-  \ execute xt if not 0
-  : @?EXEC ( xt -- ) @ ?DUP IF
-    ( xt ) EXECUTE
-    THEN
-  ;
-
   \ get MODBUS FC
   : mbfc ( -- c )
     rtbuf 1+ C@
   ;
 
-  \ 1st MODBUS FC parameter
-  : mbp1 ( -- n )
-    mbp @
-  ;
-
-  \ 2nd MODBUS FC parameter
-  : mbp2 ( -- n )
-    mbp 2+ @
-  ;
-
-  \ MODBUS write response (e.g FC05, FC06, FC15, FC16)
-  : MBWR  ( -- )
-    mbp1 tx+ mbp2 tx+  \ copy 1st and 2nd parameter
-  ;
-
-  \ true if n in range mbp1,mbp2, else false and MODBUS EC=2
-  : mbrange? ( n -- b )
-    -1 ( b ) SWAP mbp1 mbp2 + - 0< IF
-      2 MBEC ( b ) NOT
-    THEN
-  ;
-
-  \ MB loop (xt) from mbp1 to mbp1+mbp2
-  : mbloop ( xt -- )
-    mbp1 mbp2 OVER + SWAP  DO
-      ( xt ) I OVER EXECUTE
-    LOOP
-    ( xt ) DROP
-  ;
-
-  \ MB looped bit read with action xt, build response (FC01, FC02, FC03, FC04)
-  : mbread ( xt bpu -- )
-    ( xt bpu ) DUP mbp2 * ( bpu bits )
-    \ N* as quantity of bits / 8, if the remainder is different of 0 => N=N+1
-    ( bits ) 1- 8 / 1+ ( N* ) DUP txc+
-    ( bpu N* ) SWAP ( bpu ) 1 = IF
-       ( N* ) 1- FOR 0 txc+ NEXT  \ init bytes in response with 0
-    ELSE
-       ( N* ) DROP  \ not a bitfield, no memory init
-    THEN
-    ( xt ) mbloop
-  ;
-
   \ MODBUS protocol handler
   : MBPROTO ( -- )
     rtbuf rxp @ - ( rx )