BSB: An attempt at sending

[home-hw.git] / lib / modbus.c

diff --git a/lib/modbus.c b/lib/modbus.c
index c6336460d307d1a8fe814e77b3159409ddaeb113..28f976df7b8e43f2b619043421c44aa5b5f8d3e7 100644 (file)
--- a/lib/modbus.c
+++ b/lib/modbus.c
@@ -66,6 +66,14 @@
 #endif
 #endif
 
+// Debugging
+// #define MODBUS_DEBUG
+
+#ifdef MODBUS_DEBUG
+#define DEBUG debug_printf
+#else
+#define DEBUG(xxx, ...) do { } while (0)
+#endif
 /*** State ***/
 
 enum mb_state {
@@ -88,6 +96,7 @@ static byte *rx_frame_end;
 static byte tx_buf[MODBUS_TX_BUFSIZE];
 static u16 tx_size;
 static u16 tx_pos;
+static byte pending_error;
 
 static bool check_frame(void);
 static void process_frame(void);
@@ -101,6 +110,7 @@ static void rx_init(void)
        rx_bad = 0;
        usart_set_mode(MODBUS_USART, USART_MODE_RX);
        usart_enable_rx_interrupt(MODBUS_USART);
+       modbus_ready_hook();
 }
 
 static void rx_done(void)
@@ -127,6 +137,8 @@ static void tx_done(void)
 
 void modbus_init(void)
 {
+       DEBUG("MODBUS: Init\n");
+
        timer_set_prescaler(MODBUS_TIMER, CPU_CLOCK_MHZ-1);     // 1 tick = 1 μs
        timer_set_mode(MODBUS_TIMER, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_DOWN);
        timer_update_on_overflow(MODBUS_TIMER);
@@ -159,6 +171,8 @@ void MODBUS_USART_ISR(void)
                        if (status & (USART_SR_FE | USART_SR_ORE | USART_SR_NE)) {
                                rx_bad = 1;
                        } else if (rx_size < MODBUS_RX_BUFSIZE) {
+                               if (!rx_size)
+                                       modbus_frame_start_hook();
                                rx_buf[rx_size++] = ch;
                        } else {
                                // Frame too long
@@ -212,9 +226,12 @@ void modbus_loop(void)
                return;
        }
 
+       DEBUG("MODBUS: < dest=%02x func=%02x len=%u\n", rx_buf[0], rx_buf[1], rx_size);
+
        if (rx_buf[0] == MODBUS_OUR_ADDRESS) {
                // Frame addressed to us: process and reply
                process_frame();
+               DEBUG("MODBUS: > status=%02x len=%u\n", tx_buf[1], tx_size);
                tx_init();
        } else if (rx_buf[0] == 0x00) {
                // Broadcast frame: process, but do not reply
@@ -305,11 +322,13 @@ static bool check_frame(void)
 {
        if (rx_bad) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: RX bad\n");
                return false;
        }
        
        if (rx_size < 4) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: RX undersize\n");
                return false;
        }
 
@@ -317,6 +336,7 @@ static bool check_frame(void)
        u16 rx_crc = (rx_buf[rx_size-2] << 8) | rx_buf[rx_size-1];
        if (crc != rx_crc) {
                // FIXME: Error counters?
+               DEBUG("MODBUS: Bad CRC\n");
                return false;
        }
 
@@ -351,6 +371,7 @@ enum mb_error {
        ERR_ILLEGAL_FUNCTION = 0x01,
        ERR_ILLEGAL_DATA_ADDRESS = 0x02,
        ERR_ILLEGAL_DATA_VALUE = 0x03,
+       ERR_SLAVE_DEVICE_FAILURE = 0x04,
 };
 
 static uint read_remains(void)
@@ -459,6 +480,9 @@ static void func_write_single_coil(void)
                return report_error(ERR_ILLEGAL_DATA_VALUE);
 
        modbus_set_coil(addr, value);
+
+       write_u16(addr);
+       write_u16(value);
 }
 
 static void func_write_single_register(void)
@@ -473,6 +497,9 @@ static void func_write_single_register(void)
                return report_error(ERR_ILLEGAL_DATA_ADDRESS);
 
        modbus_set_holding_register(addr, value);
+
+       write_u16(addr);
+       write_u16(value);
 }
 
 static void func_write_multiple_coils(void)
@@ -493,6 +520,9 @@ static void func_write_multiple_coils(void)
 
        for (u16 i = 0; i < count; i++)
                modbus_set_coil(start + i, rx_frame[i/8] & (1U << (i%8)));
+
+       write_u16(start);
+       write_u16(count);
 }
 
 static void func_write_multiple_registers(void)
@@ -513,6 +543,9 @@ static void func_write_multiple_registers(void)
 
        for (u16 i = 0; i < count; i++)
                modbus_set_holding_register(start + i, read_u16());
+
+       write_u16(start);
+       write_u16(count);
 }
 
 static void func_mask_write_register(void)
@@ -530,6 +563,10 @@ static void func_mask_write_register(void)
        u16 reg = modbus_get_holding_register(addr);
        reg = (reg & and_mask) | (or_mask & ~and_mask);
        modbus_set_holding_register(addr, reg);
+
+       write_u16(addr);
+       write_u16(and_mask);
+       write_u16(or_mask);
 }
 
 static void func_read_write_multiple_registers(void)
@@ -650,6 +687,7 @@ static void process_frame(void)
        tx_buf[0] = MODBUS_OUR_ADDRESS;
        tx_buf[1] = rx_buf[1];
        tx_size = 2;
+       pending_error = 0;
 
        switch (func) {
                case FUNC_READ_COILS:
@@ -689,6 +727,15 @@ static void process_frame(void)
                        report_error(ERR_ILLEGAL_FUNCTION);
        }
 
+       // Is there a deferred error pending?
+       if (pending_error)
+               report_error(pending_error);
+
        // Finish reply frame
        write_u16(crc16(tx_buf, tx_size));
 }
+
+void modbus_slave_error(void)
+{
+       pending_error = ERR_SLAVE_DEVICE_FAILURE;
+}