From e651a10fb00874c3dd93ef07429a16b5490a7d88 Mon Sep 17 00:00:00 2001
From: Peter M. Groen <pgroen@nuc64.osdev.nl>
Date: Sun, 25 Sep 2022 20:29:02 +0200
Subject: [PATCH] Implmenting ModbusBase class

---
 src/modbusbase.cpp | 38 +++++++++++++++++++++++++++++++++++---
 src/modbusbase.h   | 30 +++++++++++++++++++++++-------
 2 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/src/modbusbase.cpp b/src/modbusbase.cpp
index e3bd4bc..90a6f1a 100644
--- a/src/modbusbase.cpp
+++ b/src/modbusbase.cpp
@@ -19,12 +19,43 @@ int ModbusBase::readInputBits(uint16_t address, uint16_t amount, bool *buffer)
 
 int ModbusBase::readHoldingRegisters(uint16_t address, uitn16_t amount, uint16_t *buffer)
 {
-
+    if (m_connected)
+    {
+        modbusRead(address, amount, READ_REGS);
+        uint8_t to_rec[MAX_MSG_LENGTH];         // <-- Transport layer dependent .. ?
+        ssize_t result = modbusReceive(to_rec);
+        if (result == -1)
+        {
+            setBadConnection();
+            return BAD_CON;
+        }
+        modbusErrorHandle(to_rec, READ_REGS);
+        if (err)
+        {
+            return err_no;
+        }
+        for (auto i = 0; i < amount; i++)
+        {
+            buffer[i] = ((uint16_t)to_rec[9u + 2u * i]) << 8u;
+            buffer[i] += (uint16_t)to_rec[10u + 2u * i];
+        }
+        return 0;
+    }
+    else
+    {
+        setBadConnection();
+        return BAD_CON;
+    }
 }
 
 int ModbusBase::readInputRegisters(uint16_t address, uint16_t amount, uint16_t *buffer)
 {
+    if (m_connected)
+    {
+        modbusRead(address, amount, READ_INPUT_REGS);
+        uint8_t to_rec[MSG_MAX_LENGTH];
 
+    }
 }
 
 int ModbusBase::writeCoil(uint16_t address, const bool &to_write)
@@ -68,8 +99,9 @@ int ModbusBase::modbusRead(uint16_t address, uint16_t amount, int function_code)
     uint8_t to_send[12];
     buildRequest(to_send, address, function_code);
     to_send[5] = 6;
-    to_send[10] = (uint8_t)
-    }
+    to_send[10] = (uint8_t)(amount >> 8u);
+    to_send[11] = (uint8_t)(amount & 0x00FFu);
+    return modbusSend(to_send, 12);
 }
 
 int ModbusBase::modbusWrite(uint16_t address, uint16_t amount, int function_code, const uint16_t *value)
diff --git a/src/modbusbase.h b/src/modbusbase.h
index 6b7af77..12fe5b5 100644
--- a/src/modbusbase.h
+++ b/src/modbusbase.h
@@ -69,7 +69,23 @@ public:
     // Modbus implementation(s)
     int readCoils(uint16_t address, uint16_t amount, bool *buffer);     // Replace buffer with something sensible?
     int readInputBits(uint16_t address, uint16_t amount, bool *buffer); // Replace buffer with something sensible?
+
+    /*!
+     * Read Holding Registers 
+     * MODBUS Function 0x03 
+     * \param address  - Reference Address
+     * \param amount   - Amount of Registers to Read
+     * \param buffer   - Buffer to Store Data Read from Registers
+     */
     int readHoldingRegisters(uint16_t address, uitn16_t amount, uint16_t *buffer);
+
+    /*!
+     * Read Input Registers 
+     * MODBUS Function 0x04 
+     * \param address - Reference Address
+     * \param amount  - Amount of registers to read
+     * \param buffer  - Buffer to store Data Read from Registers
+     */
     int readInputRegisters(uint16_t address, uint16_t amount, uint16_t *buffer);
 
     int writeCoil(uint16_t address, const bool &to_write);
@@ -95,17 +111,17 @@ private:        // Methods
      * 
      * \return int 
      */
-    int         modbusWrite(uint16_t address, uint16_t amount, int function_code, const uint16_t *value);
+    int                 modbusWrite(uint16_t address, uint16_t amount, int function_code, const uint16_t *value);
     virtual ssize_t     modbusSend(uint8_t *to_send, size_t length) = 0;
     virtual ssize_t     modbusReceive(uint8_t *buffer) const = 0;
 
-    void        modbusErrorHandle(const uint8_t *msg, int function_code);
-    void        setBadConnection();
-    void        setBadInput();
+    void                modbusErrorHandle(const uint8_t *msg, int function_code);
+    void                setBadConnection();
+    void                setBadInput();
 
 private:        // Members (Giggity!)
-    bool        m_connected{};
-    uint32_t    m_msg_id{};
-    int         m_slaveId{};
+    bool                m_connected{};
+    uint32_t            m_msg_id{};
+    int                 m_slaveId{};
 
 };
--
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