Fernando Cosentino / Tinymal_Modbus

Simple, tiny minimal library to implement a ModBus slave in mbed.

tinymal_modbus.h@0:4f5da8a923c4, 2019-02-22 (annotated)

Committer:
fbcosentino
Date:
Fri Feb 22 14:31:13 2019 +0000
Revision:
0:4f5da8a923c4
Initial commit

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fbcosentino 0:4f5da8a923c4 1 /** @file tinymal_modbus.h
fbcosentino 0:4f5da8a923c4 2 * Library to implement a ModBus slave in mbed.
fbcosentino 0:4f5da8a923c4 3 * @note Currently supports 38400 baud rate only.
fbcosentino 0:4f5da8a923c4 4 *
fbcosentino 0:4f5da8a923c4 5 * @author Fernando Cosentino
fbcosentino 0:4f5da8a923c4 6 * os.mbed.com/users/fbcosentino
fbcosentino 0:4f5da8a923c4 7 *
fbcosentino 0:4f5da8a923c4 8 * Example:
fbcosentino 0:4f5da8a923c4 9 * @code
fbcosentino 0:4f5da8a923c4 10 * #include "mbed.h"
fbcosentino 0:4f5da8a923c4 11 * #include "tinymal_modbus.h"
fbcosentino 0:4f5da8a923c4 12 *
fbcosentino 0:4f5da8a923c4 13 * // pins are for LPC11U35
fbcosentino 0:4f5da8a923c4 14 * Serial rs485(P0_19, P0_18); // a serial port object
fbcosentino 0:4f5da8a923c4 15 * DigitalOut driver_pin(P0_2); // direction driver pin
fbcosentino 0:4f5da8a923c4 16 * DigitalOut coil1(P0_20); // a coil - this is the application
fbcosentino 0:4f5da8a923c4 17 *
fbcosentino 0:4f5da8a923c4 18 * int main() {
fbcosentino 0:4f5da8a923c4 19 * rs485.baud(38400);
fbcosentino 0:4f5da8a923c4 20 * tinymod_Init(&rs485, &driver_pin);
fbcosentino 0:4f5da8a923c4 21 * tinymod_Address(10);
fbcosentino 0:4f5da8a923c4 22 *
fbcosentino 0:4f5da8a923c4 23 * // tiny_regs is the array containing the modbus registers
fbcosentino 0:4f5da8a923c4 24 * tiny_regs[0] = 0; // Sets an initial value to register 0
fbcosentino 0:4f5da8a923c4 25 *
fbcosentino 0:4f5da8a923c4 26 * while(1) {
fbcosentino 0:4f5da8a923c4 27 * // call this periodically to process the messages
fbcosentino 0:4f5da8a923c4 28 * tinymod_Check();
fbcosentino 0:4f5da8a923c4 29 *
fbcosentino 0:4f5da8a923c4 30 * // make the coil reflect the internal modbus register
fbcosentino 0:4f5da8a923c4 31 * if (tiny_regs[0] > 0) {
fbcosentino 0:4f5da8a923c4 32 * coil1 = 1;
fbcosentino 0:4f5da8a923c4 33 * }
fbcosentino 0:4f5da8a923c4 34 * else {
fbcosentino 0:4f5da8a923c4 35 * coil1 = 0;
fbcosentino 0:4f5da8a923c4 36 * }
fbcosentino 0:4f5da8a923c4 37 * }
fbcosentino 0:4f5da8a923c4 38 * }
fbcosentino 0:4f5da8a923c4 39 * @endcode
fbcosentino 0:4f5da8a923c4 40 */
fbcosentino 0:4f5da8a923c4 41
fbcosentino 0:4f5da8a923c4 42 #include "mbed.h"
fbcosentino 0:4f5da8a923c4 43
fbcosentino 0:4f5da8a923c4 44 #define TINYMOD_NUM_REGS 16
fbcosentino 0:4f5da8a923c4 45
fbcosentino 0:4f5da8a923c4 46 #define TINYMOD_MODE_SLAVE 0
fbcosentino 0:4f5da8a923c4 47 #define TINYMOD_MODE_MASTER 1
fbcosentino 0:4f5da8a923c4 48
fbcosentino 0:4f5da8a923c4 49 #define MODBUS_FUNC_READ 3
fbcosentino 0:4f5da8a923c4 50 #define MODBUS_FUNC_WRITE_SINGLE 6
fbcosentino 0:4f5da8a923c4 51 #define MODBUS_FUNC_WRITE_MULT 16
fbcosentino 0:4f5da8a923c4 52
fbcosentino 0:4f5da8a923c4 53
fbcosentino 0:4f5da8a923c4 54 extern uint8_t tinymod_address;
fbcosentino 0:4f5da8a923c4 55 extern int tinymod_mode;
fbcosentino 0:4f5da8a923c4 56
fbcosentino 0:4f5da8a923c4 57
fbcosentino 0:4f5da8a923c4 58 /**
fbcosentino 0:4f5da8a923c4 59 * Array storing the register values - your application will work with this.
fbcosentino 0:4f5da8a923c4 60 */
fbcosentino 0:4f5da8a923c4 61 extern uint16_t tiny_regs[TINYMOD_NUM_REGS];
fbcosentino 0:4f5da8a923c4 62
fbcosentino 0:4f5da8a923c4 63
fbcosentino 0:4f5da8a923c4 64 /**
fbcosentino 0:4f5da8a923c4 65 * Initialises the internal Modbus receiver based on the specified serial port
fbcosentino 0:4f5da8a923c4 66 * direction driver objects. You must initialise those objects yourself before
fbcosentino 0:4f5da8a923c4 67 * instancing the tinymal modbus object.
fbcosentino 0:4f5da8a923c4 68 *
fbcosentino 0:4f5da8a923c4 69 * @param ser_obj Serial instance of the Serial class.
fbcosentino 0:4f5da8a923c4 70 * @param driver_obj Digital output pin instance of the DigitalOut class
fbcosentino 0:4f5da8a923c4 71 */
fbcosentino 0:4f5da8a923c4 72 void tinymod_Init(Serial * ser_obj, DigitalOut * driver_obj);
fbcosentino 0:4f5da8a923c4 73
fbcosentino 0:4f5da8a923c4 74 /**
fbcosentino 0:4f5da8a923c4 75 * Sets the listening address for this device. Valid addresses are in the
fbcosentino 0:4f5da8a923c4 76 * range of 0 - 247 decimal (0x00 - 0xF7).
fbcosentino 0:4f5da8a923c4 77 *
fbcosentino 0:4f5da8a923c4 78 * @param addr Address this device should respond to (0 - 247)
fbcosentino 0:4f5da8a923c4 79 */
fbcosentino 0:4f5da8a923c4 80 void tinymod_Address(uint8_t addr);
fbcosentino 0:4f5da8a923c4 81
fbcosentino 0:4f5da8a923c4 82 /**
fbcosentino 0:4f5da8a923c4 83 * Internally processes any received messages - you must call this as often
fbcosentino 0:4f5da8a923c4 84 * as possible (ideally once per main loop if your main loop is short).
fbcosentino 0:4f5da8a923c4 85 * Messages are not automatically processed to keep interrupt handling to the
fbcosentino 0:4f5da8a923c4 86 * bare minimum, so you have the freedom to decide when you are going to spend
fbcosentino 0:4f5da8a923c4 87 * processor time processing the message via this function call.
fbcosentino 0:4f5da8a923c4 88 */
fbcosentino 0:4f5da8a923c4 89 void tinymod_Check(void);