Buffers Definition

2 types of buffers are to be considered:

  • Time stamping module internal buffer. This buffer parameters are set in Control Expert for the BMX ERT 1604 T and BMX CRA 312 10 modules.

  • PLC event raw buffer, set in GET_TS_EVT_X function block (CTRL_STAMP parameter)

Time Stamping Module Internal Buffer Behavior on Buffer Full

A time stamping module internal buffer should not be full in normal case, but, it can become full in case of disconnection between the module and the PLC for example.

A buffer full is diagnosed via BUFF_FULL and TS_BUF_FILLED_PCTAGE parameters.

Time stamping modules behavior on internal buffer full:

  • BMX ERT 1604 T stops the recording on buffer full. The process value changes are lost until the system is working normally again.

  • BMX CRA 312 10 offers 2 possibilities:

    • Stop the recording on buffer full, the process value changes are lost until the system is working normally again.

    • Overwrite buffer on buffer full, the oldest value changes are lost until the system is working normally again.

Buffer Full Event Sequence

NOTE: The BMX ERT 1604 T module buffer behavior is specific. For more details, refer to Behavior Mode topic

The following diagram explains the BMX CRA 312 10 buffer management in the applicative time stamping solution:

Clear BMX ERT 1604 T Internal Buffer

If the internal module buffer needs to be cleared for another application, use one of the following solutions depending on the module location:

  • BMX ERT 1604 T in the PLC (local drop):

    • Execute GET_TS_EVT_M function block with CMD input parameter set to 1, or

    • Set %Qr.m.0.0 or CLR_EVENT_BUF in T_ERT_TS_MOD parameter in IODDT instance to 1

  • BMX ERT 1604 T in a Modicon X80 drop:

    • Execute GET_TS_EVT_Q function block with CMD input parameter set to 1, or

    • Set T_M_TIME_SYNC_ERT.CLR_EVT_BUF parameter in T_M_DIS_ERT device DDT instance to 1

NOTE: The internal buffer may also be cleared according to the corresponding operating mode behavior.
NOTE: The execution of GET_TS_EVT_X function block empties the time stamping module internal buffer by reading its events.

Clear BMX CRA 312 10 Internal Buffer

The execution of GET_TS_EVT_Q function block with CMD input parameter set to 1 clears the time stamping module internal buffer.

NOTE: The internal buffer may also be cleared according to the corresponding operating mode behavior.
NOTE: The execution of GET_TS_EVT_Q function block empties the time stamping module internal buffer by reading its events.