Setting of parameters k and w for IEC 60870-5-104
Parameters k (Maximum number of outstanding I format APDUs) and w, cannot be adjusted, while vendors recommend customers to set it to k=12 and w=8
Gabriel Michaud-Verreault commented
K: Maximum unacknowledged transmitted APDUs. The master does not send more APDUs if the maximum number of ADPUs have been transmitted and have not been acknowledged.
W: Maximum unacknowledged received APDUs. This setting works in conjunction with T2 to limit how often the master acknowledges APDUs. Increasing this setting can reduce bandwidth required for acknowledging