Mitsubishi Serial Communication Interface API

The DASTEC Corporation Mitsubishi Serial Communication Interface API allows the user to implement bi-directional communications to exchange data between applications running on a PC-based or embedded system with other peer devices supporting the Mitsubishi Serial protocol. The peer devices can be Mitsubishi A, Q or FX Series PLC(s), other host computers or even other system applications using the API.

The Mitsubishi Serial Communication Interface API enables a system to acts as a client to other Mitsubishi peers, initiating read and write operations on behalf of the system applications. The API also allows the system to emulate an Mitsubishi A, Q or FX Series PLC to respond to read and write requests and thus acts as a "virtual PLC" to other Mitsubishi Serial peers. The API is available for various combinations of operating systems and hardware platforms and can be used with C, C++, C# or Visual Basic.

The API consists of two component functionalities, client side and server side. The client side functionality is implemented with a single API library. Server side functionality is implemented with a library/executable pair. Together these components manage all aspects of the protocol and data exchange including responding to peers with proper acknowledgements, error/success codes and protocol data byte ordering. The system application need only to deal with the data values exchanged in native byte order. The user can employ either the API's client, server or both functionalities with minimal code implementation.

The Mitsubishi Serial Communication Interface API supports the following protocol function commands:

• "BR" or "JR" Batch Bit Read (bit devices only)
• "WR" or "QR" Batch Word Read (bit and word devices)
• "BW" or "JW" Batch Bit Write (bit devices only)
• "WW" or "QW" Batch Word Write (bit and word devices)

Client API Functionality

To exchange data with Mitsubishi Serial peers, a system application can initiate read and/or write operation(s) to peers by simply calling the client's library functions. The functions include the ability to create handle(s) for the peer device(s) and then using those handle(s) to call the clinet's library read and write functions. Operation results are returned directly to the calling application, as is data in the case of read operations.

Client API Supports:

• Defining of multiple device(s) representing Mitsubishi A, Q or FX Series peers.
• Functions to read data from and write data to defined device(s).
• Bit device data can be read/written as bytes or as packed word bits.
• Word device data can be read/written as 16-bit, 32-bit, floating-point or as ASCII values.
• Multiple user applications can use the client API simultaneously.

Server API Functionality

Using the server executable program provided as part of the API, a system can appear as a Mitsubishi Serial device (A, Q or FX Series PLC) on the network. By managing all Mitsubishi Serial communication operations, the server executable receives and responds to both read and write requests from peer devices. Data written by peers is stored into separate databases maintained by the server executable for each Mitsubishi device memory (Input (X), Output (Y), Internal Relay (M) and Data Register (D)). The data received is stored in the byte order appropriate for the system's processor. The data for read requests received from peers is retrieved and returned from these databases as well.

No user programming is required for the system to act in this server mode. Peers can read and write to the system as if it were a Mitsubishi PLC with no user application programs running. Applications have access to the server's databases indirectly through specific API library functions calls or directly via shared memory access. In this way, the user applications obtain data written from peers and can update the system's "virtual PLC's" data so that peers can retrieve it.

Server API Supports:

• Mitsubishi Device Memory: Input (X), Output (Y), Internal Relay (M) and Data Register (D). A separate database is maintained for each device memory.
• Adjustable database sizes.
• Access to databases via function calls.
• Multiple user applications can access the server databases simultaneously.

Specifications:

• Supported Mitsubishi protocol commands:
  • "BR" or "JR" Batch Bit Read (bit devices only)
  • "WR" or "QR" Batch Word Read (bit and word devices)
  • "BW" or "JW" Batch Bit Write (bit devices only)
  • "WW" or "QW" Batch Word Write (bit and word devices)
• Supports multiple, multi-thread user applications simultaneously
• Client API Supports
  • Open serial port to establish network connection to Mitsubishi Computer Link module.
  • Defining of multiple device(s) representing Mitsubishi A, Q or FX Series peers.
  • Read data from and write data to defined device(s) via different function calls.
  • Mitsubishi Device Memory: Input (X), Output (Y), Internal Relay (M), Special Relay (M), Latch Relay (L), Step Relay (S), State (S), Link Relay (B), Annunciator (F), Timer Contact (T), Timer Coil (T), Counter Contact (C), Counter Coil (C), Timer Present Value (T), Counter Present Value (C), Data Register (D), Special Register (D), Link Register (W), File Register (R) and Extension Register (R).
  • Bit device data can be read/written as bytes or as packed word bits.
  • Word device data can be read/written as 16-bit, 32-bit floating-point or as ASCII values.
  • Multiple user applications can use the client API simultaneously.
• Server API Supports:
  • Mitsubishi Device Memory: Input (X), Output (Y), Internal Relay (M) and Data Register (D).
  • Separate databases maintained for each device memory.
  • Adjustable database sizes: 0 - 65536 (2000 default).
  • Bit device data can be exchanged as bytes or as packed word bits.
  • Data Register data can be exchanged as 16-bit, 32-bit floating-point or as ASCII values.
  • Access to databases by multiple applications.
  • Access to databases via function calls.

Ordering Information

Product Name:

Mitsubishi Serial Communication Interface API

Supported Platforms Part Numbers:

Platform	Part Number
.NET/.NETCF	NET-MITSAPI

Contact DASTEC about other supported platforms or to inquire about supporting other platforms.