Remote Control 
  Copyright © ITECH Electronic Co., Ltd.  9 
 
IT-E121A Communication Module 
The DB9 interface connector on the rear panel of the DC load is TTL voltage 
level; you can use the communication module IT-E121A and a standard RS232 
extension cable to connect the DB9 interface connector of the DC load and the 
RS-232 interface connector of computer for the communication. 
IT-E121A is derived on the basis of IT-E121, the main difference between them 
is that the DB9 interface connector of the RS232 changes from female to male, 
so that can be directly connected to the standard LAN interface. 
IT-E121A communication cable 
 
IT-E122 Communication Module   
The DB9 interface connector on the rear panel of the DC load is TTL voltage 
level; IT-E122 has a USB interface (male connector B) on one end, you can use 
IT-E122 and a standard USB extension cable (type B female connector at one 
end and type A at one end) to connect the DB9 interface connector of the DC 
load and the USB interface connector of computer for the communication. 
After connecting the load and computer by USB, you need to install IT-E122 
driver (download from 
http://www.itech.sh/support/Down-3.htm?model=IT-E122%20%E5%85%89%E
9%9A%94%E7%A6%BB%E9%80%9A%E8%AE%AF%E6%8E%A5%E5%8F
%A3%E9%A9%B1%E5%8A%A8 or contact ITECH agent). The device 
manager of PC will display ‘Prolific USB-to-Serial COM Port’ after installing.