Difference between revisions of "MODBUS"
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| − | MODBUS is an application-layer messaging protocol, positioned at level 7 of the OSI model. It provides client/server communication between devices connected on different types of buses or networks. | + | MODBUS is an application-layer messaging protocol, positioned at level 7 of the OSI model. It provides client/server communication between devices connected on different types of buses or networks. <br><br> |
| − | The de facto industrial serial standard since 1979, MODBUS continues to enable millions of automation devices to communicate. Today, support for the simple and elegant structure of MODBUS continues to grow. The Internet community can access MODBUS at a reserved system port 502 on the TCP/IP stack. | + | The de facto industrial serial standard since 1979, MODBUS continues to enable millions of automation devices to communicate. Today, support for the simple and elegant structure of MODBUS continues to grow. The Internet community can access MODBUS at a reserved system port 502 on the TCP/IP stack.<br><br> |
| − | MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs | + | MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs. |
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=CNC Bender Uses MODBUS TCP/IP Enabled Modules= | =CNC Bender Uses MODBUS TCP/IP Enabled Modules= | ||
CNC Bender communicates with modules around the bender using this standard. Each module has a unique IP address. So the MODBUS data is sent to a module enclosed in a TCP/IP command. | CNC Bender communicates with modules around the bender using this standard. Each module has a unique IP address. So the MODBUS data is sent to a module enclosed in a TCP/IP command. | ||
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| + | =Other References= | ||
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| + | For of list of MODBUS errors, see [[MODBUS Exception Responses]] | ||
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Latest revision as of 21:12, 13 July 2007
Contents |
Defined
From: http://www.modbus.org/specs.php
MODBUS is an application-layer messaging protocol, positioned at level 7 of the OSI model. It provides client/server communication between devices connected on different types of buses or networks.
The de facto industrial serial standard since 1979, MODBUS continues to enable millions of automation devices to communicate. Today, support for the simple and elegant structure of MODBUS continues to grow. The Internet community can access MODBUS at a reserved system port 502 on the TCP/IP stack.
MODBUS is a request/reply protocol and offers services specified by function codes. MODBUS function codes are elements of MODBUS request/reply PDUs.
Simplified Explanation
- The MODBUS protocol was developed by MODICON in order to enable a standard way to communicate with distributed devices around a machine that are used for controlling the machine.
- The MODBUS protocol includes the ability to send a command with parameters to these various devices.
- The devices can be MOTION CONTROLLER modules, INPUT modules, OUTPUT modules, ANALOG modules, and any other module that can be used to control or sense the machinery.
So this is how data is transferred using this protocol:
------------ TCP/IP [ MODBUS DATA ] ----------------> <----------- TCP/IP [ MODBUS DATA ] --------------
CNC Bender Uses MODBUS TCP/IP Enabled Modules
CNC Bender communicates with modules around the bender using this standard. Each module has a unique IP address. So the MODBUS data is sent to a module enclosed in a TCP/IP command.
Other References
For of list of MODBUS errors, see MODBUS Exception Responses
