Summary of functions about Mitsubishi PLC QJ71PB92V

- Jan 11, 2019-

The Mitsubishi PLC module QJ71PB92V is used to connect the MELSEC-Q series programmable controller to the PROFIBUS-DP. What are its functions?

1, PROFIBUS-DPV0 function

 . I / O data communication

   Up to 125 slaves can be connected to a QJ71PB92V for up to 8192 bytes of I/O data communication.

   Note: When using the QJ71PB92V in a redundant system, it is limited to a maximum of 124 slaves.

 Communication failure information and acquisition of extended fault information

   In the case of I/O data communication, communication failure information and extended failure information when an error occurs on the slave can be easily obtained by using the buffer memory and the I/O signal.

 . Global control function

   Synchronous control of slave I/O data can be achieved by sending services (SYNC, UNSYNC, FREEZE, UNFREEZE) to each slave in the group.


2, PROFIBUS-DPV1 function

 Acyclic communication function with the slave (non-periodic data communication function)

   It refers to the function of performing read and write operations on the slave at any timing other than I/O data communication.

 . Alarm acquisition function

   For alarm or status information data that occurs in any slave station, this function can get up to eight.

 . Support for FDT/DTM technology

   The parameter read/write and status monitoring of the slave can be performed via the QJ71PB92V using the commercially available FDT.



 Slave time control function

   The QJ71PB92V is allowed to operate as a time master and the time of each slave is set.


4, data exchange function

   The high and low bytes can be exchanged in units of words when I/O data is transmitted and received.


5, data consistency function

   This function prevents I/O data from being split and incorrectly merged when reading I/O data from a slave or to a buffer memory.

  . Auto refresh setting (GX Configurator-DP).

  Dedicated instructions (BBLKRD and BBLKWR instructions).


6. Output status setting when the CPU stops error

  It can be used to set whether to stop or continue I/O data communication with the slave when a CPU stop error occurs in the QCPU or remote I/O station where the QJ71PB92V is installed.

  When the QJ71PB92V is installed in a redundant system, regardless of the setting contents, I/O data communication with the slave will continue until system A or B is down.


7. Temporary reservation station designation function

  It is not necessary to modify the parameters of the slave in GX Configurator-DP. This function can temporarily change the slave type to "reservation station".


8, redundant system corresponding function

  When the control system CPU or QJ71PB92V detects an abnormality, the control system and the standby system switch to each other to continue communication.


9, QJ71PB92D replacement function

  Used to replace the QJ71PB92D with the QJ71PB92V.

  When the QJ71PB92D fails, it is replaced by the QJ71PB92D and replaced with the QJ71PB92V.