The one channelcontrolunit can be upgraded to 2- channel or 4- channelcontrolunit.
单通道控制单元可升级为二或四通道控制单元。
2
Main controlUnit, two-channel electrometer and servo controller.
主控制器单元，带有两通道静电计和伺服控制器。
3
The control system is composed of setting unit(host computer ), digital controller , input channel (position detector)and output channel (actuating mechanism).