Siemens SIPROTEC Manual page 30

Redundant PROFIBUS DP interface
RedMSt
RedDia
RedCoT
30
Redundancy state of the PROFIBUS DP master.
The redundancy state of the PROFIBUS DP master comes from the "Control_O_1"
byte in the output telegram (ref. to chap. 1.4.1.4).
State
UNKNOWN The state can not be determined because PROFIBUS DP master and
slave are not in data exchange (communication interruption or the like).
UNDEFINED The redundancy state bits of the master in "Control_O_1" are undefined.
(bit 3 = 0 and bit 2 = 0 or bit 3 = 1 and bit 2 = 1)
PRIMARY PROFIBUS DP master is PRIMARY.
(bit 3 = 1 and bit 2 = 0 in "Control_O_1")
If the Toggle bit mechanism was activated in the parameterization then
also the first changeover from a valid Toggle bit combination to the other
valid Toggle bit combination was recognized and the Toggle bit timer is
running.
BACKUP PROFIBUS DP master is BACKUP.
(bit 3 = 0 and bit 2 = 1 in "Control_O_1")
T_PRIMARY PROFIBUS DP master is PRIMARY.
(bit 3 = 1 and bit 2 = 0 in "Control_O_1")
The Toggle bit mechanism was activated in the parameterization but is still
not started (first changeover from a valid Toggle bit combination to the
other one is still not recognized).
The slave remains in BACKUP although the master sends PRIMARY.
Table 1-6 Redundancy state of the PROFIBUS DP master
The bytes "Red_State_1" and "Red_State_2" which belong to the "Red_State" diag-
nosis data are shown.
The meaning of the individual bits in these bytes is explained in chap. 1.4.2.
The last telegram which was sent via RedCom communication to the partner module
is shown.
A byte value at the end of this line counts the number of telegrams sent via RedCom.
This telegram counter is increased by 1 after each telegram up to the value 255 and
then starts again with 0.
Telegram type
SwO.req Switchover.req (Switchover request)
Redundancy switchover request to the partner module (ref. to chap. 1.6).
SwO.cnf Switchover.cnf (Switchover confirmation)
Confirmation from partner module that a redundancy switchover of the
PROFIBUS DP slave can be executed.
Chk.req Check.req (Check request)
Telegram to the partner module for RedCom communication check and
inter-module supervision.
Chk.cnf Check.cnf (Check confirmation)
Response from the partner module to a Check.req. RedCom is OK.
Explanation
Explanation
SIPROTEC PROFIBUS DP - Bus mapping 6MD662/3/4
C53000-L1840-B011-03