System information

GRAVITAS SABRE SERIES
INSTALLATION &OPERATING MANUAL
Manual No. SABRE-4 Page 11 11/27/07 sabre-man
1.2.1.5 Operating status for the various positions of the MBS
The operation mode of STS is closely linked with the position of MBS. The MBS has two main contacts and three
auxiliary contacts, signals generated by the three auxiliary contacts are passed to STS for position detection. Once an
auxiliary contact is closed, the signal is logic 0, in reverse it will be logic 1. The combination of logic 0 and 1 can
produce five valid position statuses.
Position status of MBS
SW1/SW2/SW3 are the logic level signals detected by STS, the five valid status conditions are as follows:
Contacts Signals
MBS Position
SW1 SW2 SW3
Mode Define Postural Plot
P1 0 1 1 Mains Bypass
(MBP)
MBP
ISS
NORM
MSS
IBP
P2 0 0 1 Inverter Maintenance
(MSS)
MBP
ISS
NORM
MSS
IB P
P3
0 0 0 Normal Operation
(NORM)
MBP
ISS
NORM
MSS
IBP
P4
1 0 0 Mains Maintenance
(ISS)
MBP
ISS
NORM
MSS
IBP
P5
1 1 0 Inverter Bypass
(IBP)
MBP
ISS
NORM
MSS
IBP
1 0 1
0 1 0
Invalid
1 1 1
Reserved
Figure 3 MBS positions (0 = Low, 1 = High)
The STS will continuously detect the position of the MBS in order to decide the transferring action between different
modes. The STS will continuously detect whether the position of the MBS is valid. If the status is invalid, the STS
will consider the MBS faulty, it won’t enter any operation mode, and the red LED will blink at 5Hz, at the same time
the “MBS abnormal” alarm will be sent to the controller, this phenomenon won’t disappear until the detection signal
becomes normal. If the MBS is changed when the STS is running at one of the five valid positions, and this change
happens between two adjacent positions, then the STS will transfer to a different mode based on current status,
otherwise the STS won’t take any action. For example, if the MBS is at P3, the STS will take action when the MBS is
turned to P2 or P4.
Note: Be sure not to change the MBS position immediately after the STS is inserted into the rack; wait at least 5
seconds if you want to change it and ensure that the MBS remains in each consecutive position for at least 1 second at
one position.