ProSoft Technology 5105-103M-PDPS - Manual (Page 66)

Diagnostics and Troubleshooting 5105-103M-PDPS ♦ ProLinx Gateway
User Manual IEC 60870-5-103 Master to PROFIBUS Slave Gateway
Page 66 of 144 ProSoft Technology, Inc.
November 24, 2010
Baud Rate Monitoring
The located baud rate is constantly monitored in "Baud_Control." The watchdog
is reset for each error-free telegram to its own station address. The monitoring
time results from multiplying both "WD_Baud_Control_Val" (user sets the
parameters) by the time base (10 ms). If the timer expires, WD_SM again goes
to "Baud_Search". If the user carries out the DP protocol (DP_Mode = 1, see
Mode register 0) with SPC3, the watchdog is used for the "DP_Control" state,
after a "Set_Param telegram" was received with an enabled response time
monitoring "WD_On = 1." The watchdog timer remains in the baud rate
monitoring state when there is a switched off "WD_On = 0" master monitoring.
The PROFIBUS DP state machine is also not reset when the timer runs out. That
is, the slave remains in the DATA_Exchange state, for example.
Response Time Monitoring
The 'DP_Control' state serves response time monitoring of the DP master
(Master_Add). The set monitoring times results from multiplying both watchdog
factors and multiplying the result with the momentarily valid time base (1 ms or
10 ms):

TWD = (1 ms or 10 ms) * WD_Fact_1 * WD_Fact_2 (See byte 7 of the
parameter setting telegram)
The user can load the two watchdog factors (WD_Fact_1, and WD_Fact_2) and
the time base that represents a measurement for the monitoring time via the
’Set_Param telegram' with any value between 1 and 255.
EXCEPTION: The WD_Fact_1=WD_Fact_2=1 setting is not permissible. The
circuit does not check this setting.
Monitoring times between 2 ms and 650 s - independent of the baud rate - can
be implemented with the permissible watchdog factors. If the monitoring time
runs out, the SPC3 goes again to 'Baud_Control,' and the SPC3 generates the
'WD_DP_Control_Timeout-Interrupt'. In addition, the DP_State machine is reset,
that is, generates the reset states of the buffer management.
If another master accepts SPC3, then there is either a switch to 'Baud_Control"
(WD_On = 0), or there is a delay in 'DP_Control' (WD_On = 1), depending on the
enabled response time monitoring (WD_On = 0).