#12 fix node, baud rate, input handler

MBPROTO

@@ -8,8 +8,15 @@
 NVM
   VARIABLE mbnode  \ MODBUS node id
   VARIABLE crcerr  \ CRC error counter
-  VARIABLE mbact   \ action XT for generic extensions (e.g. debugging)
-  VARIABLE mbdef   \ action XT for default handler
+  VARIABLE mbpre   \ xt for FC preparation (e.g. reading inputs)
+  VARIABLE mbact   \ xt for oputput action (e.g. output, debugging)
+  VARIABLE mbdef   \ xt for default handler
+
+  \ execute xt if not 0
+  : @?EXEC ( xt -- ) @ ?DUP IF
+    ( xt ) EXECUTE
+    THEN
+  ;
 
   \ get MODBUS FC
   : mbfc ( -- c )
@@ -83,28 +90,28 @@ NVM
   \ MODBUS protocol handler
   : MBPROTO ( -- )
     rxbuf rxp @ - ( rx )
-    1 TIM tstamp @ - <   AND ( message trigger )
+    1 TIM tstamp @ - < AND ( message trigger )
     IF
       rxp @ 2- ( a1 ) DUP rxbuf ( a1 a1 a0 )
       MBCRC ( a1 crc-le ) SWAP @ = ( crc OK )
       ( crc-ok ) IF
         mbnode @ rxbuf C@ = IF  \ node address match
-          rxbuf    C@  ( DUP  ." S: " . CR )     txc+
-          rxbuf 1+ C@  DUP txc+  ( fc )
+          mbpre @?EXEC    \ preparation handler, e.g. read inputs
+          rxbuf    C@     txc+
+          rxbuf 1+ C@ DUP txc+  ( fc )
           DUP 1 17 WITHIN IF
-             FC>XT @ EXECUTE
+             FC>XT @?EXEC \ get and execute FC handler
           ELSE
-            FCDEF
+            FCDEF         \ default handler
           THEN
           tbp @ txbuf ( a1 a0 ) MBCRC ( CRC-LE ) tx+
-          mbact @ ?DUP IF
-            ( xt ) EXECUTE
-          THEN
-          send rxres
+          mbact @?EXEC    \ action handler, e.g. write outputs
+          send
         THEN
       ELSE
         1 crcerr +!
       THEN
+      rxres
     THEN
   ;
 
@@ -122,6 +129,7 @@ WIPE RAM
 #require MBPROTO
 
 RAM
+#require WIPE
 #require MBRESET
 MBRESET   \ Reset the MODBUS Function Code table
 
@@ -151,5 +159,5 @@ NVM
     [ ' MBPROTO ] LITERAL 'IDLE ! \ run MB protocol handler as idle task
   ;
 
-  ' init    'BOOT !
+  ' init 'BOOT !
 WIPE RAM

README.md

@@ -20,7 +20,7 @@ The STM8S001J3RS485 board is a tiny MODBUS node based on the STM8S001J3M3 "Low D
 
 [![STM8S001J3RS485](https://raw.githubusercontent.com/TG9541/stm8s001rs485/master/doc/STM8S001J3_RS485_front.png)](https://github.com/TG9541/stm8s001rs485)
 
-This is work in progress. 
+This is work in progress.
 
 The code can be built and transferred to the devide by running `make -f forth.mk BOARD=STM8S001J3RS485 flash`. After flashing the `BUSCTRL` file in the board configuration folder should be transferred using e4thcom and a 2-wire connection through PC5. After that `main.fs` in the project root folder can be transferred.
 
@@ -42,9 +42,9 @@ FC | Description | Support
 **3** | **Read Holding Registers** | implemented (variables in RAM)
 **4** | **Read Input Registers** | implemented
 **5** | **Write Single Coil** | implemented
-6 | Write Single (Holding) Register | (write issue if needed)
+**6** | **Write Single (Holding) Register** | implemented
 **15** | **Write Multiple Coils** | implemented
-**16** | **Write Multiple Registers** | implemented
+16 | **Write Multiple Registers** | partial
 
 Currently there are no diagnostic functions and communication properties have to be hard coded.
 
@@ -78,5 +78,6 @@ The code is organized in the following execution domains:
 * fixed-rate background task for I/O logic (asynchronous to MODBUS)
 * foreground "idle mode" MODBUS protocol handler
 * foreground command line interface (CLI) through independent COM port provided by STM8 eForth
+* handlers for MODBUS I/O: `mbpre` for input, `mbact` for output actions)
 
-The different concerns are separeted in the code - it's even possible to change FC handlers through the CLI without restarting the application!
+The different concerns are separeted in the code - FC handlers can be changed through the CLI without restarting the application!

main.fs

@@ -1,13 +1,19 @@
 #require MBSERVER
 
-  2 CONSTANT BAUD9600
+  $4000  CONSTANT  EE_NODE
+  $4002  CONSTANT  EE_BAUD
 
 NVM
   \ --- MODBUS server startup
 
   : init ( -- )
-    BAUD9600 UARTISR
-    1 mbnode !
+    EE_NODE @ DUP 0 256 WITHIN NOT IF
+      DROP 1  \ out of range - use default
+    THEN
+    ( n ) mbnode !
+
+    EE_BAUD @ ( #BR ) UARTISR
+
     MBSERVER
   ;