User Manual

1.1.7 1/2/3/4/5/6/7-port Addressable RS-232 Converter?
The 4521 is used as an addressable RS-232 converter. It can assign an
address to any RS-232 device in the same RS-485 network. Because the
firmware of the 4521 cannot be modified & the application is different case by
case, many customers complain about the limitations of the 4521. The 7521
series are designed to act as a “1/2/3/4/5/6/7 port Addressable RS-232
Converter”. The firmware of the 7521 series can be modified based on the
user’s special requirements. The onboard industry D/I/O can be used to control
the local devices for emergency conditions. So, the 7521
series can solve
nearly every “Addressable RS-232 Converter” application.
1.1.8 7521 series = Embedded Controller?
The 7521 series is really an embedded controller before downloading any
firmware. After downloading the firmware, the 7521 series acts as an
“Addressable RS-232 Converter”. The
7521/7522/7523 has the 3000V
isolation on the RS-485 port. In almost all areas, the 7521
is equivalent to
the 7188XC+7510. So the 7521 series can be used as an embedded controller
with isolation RS-485 port.
7521/2/2A/3/4/7 Series Hardware User’s Manual, Ver. 1.5 Sep/2002, 7Mh-001-15 -----10