ProSoft Technology MVI56-PDPS - Manual (Page 65)

Reference MVI56-PDPS ♦ ControlLogix Platform
Profibus DP Slave Communication Module
ProSoft Technology, Inc. Page 65 of 88
April 22, 2008
00 = 'Wait_Prm' state
01 = 'Wait_Cfg' state
10 = 'DATA_EX' state
11 = Not possible
WD-State
Watchdog-State-Machine state Bits
6,7
00 = 'Baud_Search' state
01 = 'Baud_Control' state
10 = 'DP_Control' state
11 = Not possible
Further explanation of Status Register [0]: Word 9 Bit states
Bit 0
Offline/Passive-idle
ƒ
0 = SPC3 exits offline and goes to passive-idle. The idle timer and Wd timer
go offline.
ƒ 1= SPC3 exits offline and goes to passive-idle. The idle timer and Wd timer
are started.
Bit 4, 5
ƒ
10 = Data Exchange State is Normal. The SPC3 has a correct configuration.
Bits 6, 7
ƒ
Watchdog Timer
ƒ Automatic Baud Rate Identification
The SPC3 is able to identify the baud rate automatically. The "baud search" state
is located after each RESET and also after the watchdog (WD) timer has run out
in the "Baud_Control_state." As a rule, SPC3 begins the search for the set rate
with the highest baud rate. If no SD1 telegram, SD2 telegram, or SD3 telegram
was received completely and without errors during the monitoring time, the
search continues with the next lowest baud rate.
After identifying the correct baud rate, SPC3 switches to the "Baud_Control"
state and monitors the baud rate. The monitoring time can be parameterized
(WD_Baud_Control_Val). The watchdog works with a clock of 100 Hz (10
milliseconds). The watchdog resets each telegram received with no errors to its
own station address. If the timer runs out, SPC3 again switches to the baud
search state.