Modbus notes - Revision history

Ted: Add link to rotronic.com.

2025-05-02T04:40:29Z

Add link to rotronic.com.

2024-07-02T17:04:19Z

2024-07-02T16:58:37Z

Add missed URL.

2024-07-02T16:57:06Z

How to specify preference of library path to C compiler and linker.

2024-06-29T00:20:16Z

Add to 2024 Modbus notes, focus on libmodbus example code snippets.

2024-06-28T23:49:36Z

Note older material to be moved or removed.

2024-06-28T00:38:08Z

2024-06-27T17:10:06Z

Minor formatting.

2024-06-27T13:46:27Z

Minor formatting.

2024-06-27T13:46:08Z

Minor impromptu markup for visual fencing.

← Older revision		Revision as of 04:40, 2 May 2025
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	* https://ipc2u.com/articles/knowledge-base/modbus-rtu-made-simple-with-detailed-descriptions-and-examples/		* https://ipc2u.com/articles/knowledge-base/modbus-rtu-made-simple-with-detailed-descriptions-and-examples/
		+
		+	Rotronic site which summarizes Modbus address ranges for coils, registers and related:
		+
		+	* https://service.rotronic.com/manual/modbus-definitions.html
		+
		+

	This IPC2U site combined with code snippets from a Github gist authored and shared by J Grossholtz is sufficient to write a C program which can make a PC act as a Modbus enabled device. While compiling an first test program using this library, encountered need to include library path to gcc.		This IPC2U site combined with code snippets from a Github gist authored and shared by J Grossholtz is sufficient to write a C program which can make a PC act as a Modbus enabled device. While compiling an first test program using this library, encountered need to include library path to gcc.

@@ Line 25: / Line 25: @@
 *  https://gist.github.com/JGrossholtz/d1d02a87d535d7772139
-On systems supporting standard C and its libraries, `libmodbus` may be used to create programs which act as Modbus controllers (sending commands) and or peripherals (responding to commamds):
+On systems supporting standard C and its libraries, `libmodbus` may be used to create programs which act as Modbus controllers (sending commands) and or peripherals (responding to commamds).
 *  https://stackoverflow.com/questions/2726993/how-to-specify-preference-of-library-path

@@ Line 27: / Line 27: @@
 On systems supporting standard C and its libraries, `libmodbus` may be used to create programs which act as Modbus controllers (sending commands) and or peripherals (responding to commamds):
+*  https://stackoverflow.com/questions/2726993/how-to-specify-preference-of-library-path
 <!-- 2024 ENTRY END -->

@@ Line 4: / Line 4: @@
 <!-- 2024 ENTRY BEGIN -->
 The following web site does one of the better jobs of describing Modbus protocol clearly, and with multiple examples.
@@ Line 10: / Line 9: @@
 *  https://ipc2u.com/articles/knowledge-base/modbus-rtu-made-simple-with-detailed-descriptions-and-examples/
-This IPC2U site combined with code snippets from a Github gist authored and shared by J Grossholtz is sufficient to write a C program which can make a PC act as a Modbus enabled device.
+This IPC2U site combined with code snippets from a Github gist authored and shared by J Grossholtz is sufficient to write a C program which can make a PC act as a Modbus enabled device.  While compiling an first test program using this library, encountered need to include library path to gcc.
@@ Line 21: / Line 25: @@
 *  https://gist.github.com/JGrossholtz/d1d02a87d535d7772139
-: # # # # # # # # # # # # # # #
+On systems supporting standard C and its libraries, `libmodbus` may be used to create programs which act as Modbus controllers (sending commands) and or peripherals (responding to commamds):
 == OVERVIEW CERCA 2019 ==

@@ Line 1: / Line 1: @@
-OVERVIEW
+== OVERVIEW ==
-This wiki article contains some notes and references on FreeModbus, an opensource C library to support a Modbus protocol stack in stand-alone applications as well as operating system and scheduler based systems.  This article also contains a number of links to more general C language references, which discuss function pointers in C, and the type defining of function pointers.
+Notes on Modbus protocol, and references to one or more Modbus protocol libraries, written in C and usable in Unix and Linux envorinments.
 <!-- 2024 ENTRY BEGIN -->
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-A 2024 amendment to these notes, on libmodbus:
+The following web site does one of the better jobs of describing Modbus protocol clearly, and with multiple examples.
 *  https://ipc2u.com/articles/knowledge-base/modbus-rtu-made-simple-with-detailed-descriptions-and-examples/
 Stackoverflow post showing libmodbus based sender and listener code snippets:
@@ Line 33: / Line 26: @@
-Older material cerca 2019:
+*  http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf
 Table of contents for local Modbus notes:

← Older revision		Revision as of 00:38, 28 June 2024
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	* https://stackoverflow.com/questions/29602698/create-a-simple-client-server-using-modbus-in-c		* https://stackoverflow.com/questions/29602698/create-a-simple-client-server-using-modbus-in-c
		+
		+	J. Grossholtz Github gist with modbus server and client sample C programs:
		+
		+	* https://gist.github.com/JGrossholtz/d1d02a87d535d7772139

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