User Manual

7000 Bus Converter User’s Manual (Version 1.8 Jan/2006, 7PH-006-18) --------------- 22
WARNING!! ERROR CONDITION 2: if the p7520 uses the same DC
power ground with nHost PC/PLC (for example, nHost PC/PLC
provide non-isolated DC power source to p7520). In this situation,
(1) The nHost PC/PLC is common ground with power ground of p7520
(2) The power ground of p7520 is common ground with rRS-485
Therefore the nHost PC/PLC is common ground with rRS-485 network.
That is to say, there is no isolation between nHost PC/PLC and rRS-485
network. So the nHost PC/PLC may be damaged if there is high voltage
transient on rRS-485 network.
OK CONDITION: If the DC power ground of p7520 or p7520R is not common
to any module, the nHost PC/PLC will be isolated from rRS-485 network in
all conditions.
The power adapter PWR-24 is designed for single 7000 series modules
only. The 24V DC output of the PWR-24 is isolated from its AC input. If the
p7520 or p7520R is connected to the PWR-24, this PWR-24 cannot connect
to the other module. Normally the nHost PC/PLC uses a switching power and
the DC output of this power supply is also isolated from its AC input. Therefore
the DC power ground of p7520 or p7520R is isolated from nHost PC/PLC.
Therefore, the nHost PC/PLC is isolated from rRS-485 network in all condition.
nHost PC/PLC is isolated
from rRS-485 network
for p7520 or p7520R in
all condition