Toshiba GRL100-701B Instruction Manual page 165

3.1.4.2 IO2 Module
As shown in Figure 3.1.4.2, the IO2 module incorporates 3 photo-coupler circuits (BI) for binary
input signals, 14 auxiliary relays (13 BOs and FAIL) for binary output signals and an RS485
transceiver.
The auxiliary relay FAIL has one normally closed contact, and operates when a relay failure or
abnormality in the DC circuit is detected. Each BO has one normally open contact. BO13 is a
high-speed operation type.
The RS485 is used for the link with communication system such as RSM (Relay Setting and
Monitoring) or IEC60870-5-103 etc. The external signal is isolated from the relay internal
signal.
IO2 module
Photo-coupler
BI
Binary
input
BI
signals
BI
(× 3)
Auxiliary relay
BO
BO
FAIL
BO13
RS-485
Figure 3.1.4.2 IO2 Module
 164 
6 F 2 S 0 8 5 0
Binary
output
signals
(BO × 13,
FAIL × 1)
Link with serial
communication
system such as
RSM or
IEC103, etc.