Sutter Instrument MPC-200 - External Control; Setup and Communication

MPC-385 SERIES OPERATION MANUAL – REV. 3.21K (20201120)
31
5. EXTERNAL CONTROL
5.1 General
Controlling the MPC-385 externally via computer is accomplished by sending commands to
the MPC-200 controller over the USB interface between the computer and the USB
connector on the rear of the ROE-200 that’s connected to the MPC-200 controller. The USB
device driver for Windows is downloadable from Sutter Instrument’s web site
(www.sutter.com
). The MPC-385 (MPC-200) requires USB CDM (Combined Driver Model)
Version 2.10.00 or higher. The CDM device driver for the MPC-385 (MPC-200) consists of two
device drivers: 1) USB device driver, and 2) VCP (Virtual COM Port) device driver. Install the
USB device driver first, followed by the VCP device driver. The VCP device driver provides a
serial RS-232 I/O interface between a Windows application and the MPC-385 (MPC-200).
Although the VCP device driver is optional, its installation is recommended even if it is not
going to be used. Once installed, the VCP can be enabled or disabled.
The CDM device driver package provides two I/O methodologies over which communications
with the controller over USB can be conducted: 1) USB Direct (D2XX mode), or 2) Serial RS-
232 asynchronous via the VCP device driver (VCP mode). The first method requires that the
VCP device driver not be installed, or if installed, that it be disabled. The second method
requires that the VCP be installed and enabled.
5.2 Virtual COM Port (VCP) Serial Port Settings
The following table lists the required RS-232 serial settings for the COM port (COM3,
COM5, etc.) generated by the installation or enabling of the VCP device driver.
Table 5-1. USB-VCP interface serial port settings.
Property
Setting
Data (“Baud”) Rate (bits per second (bps))
128000
Data Bits
8
Stop Bits
1
Parity
None
Flow Control
None
The settings shown in the above table can be set in the device driver’s properties (via the
Device Manager if in Windows) and/or programmatically in your application.
5.3 Protocol and Handshaking
Command sequences do not have terminators. All commands return an ASCII CR (Carriage
Return; 13 decimal, 0D hexadecimal) to indicate that the task associated with the command
has completed. When the controller completes the task associated with a command, it sends
ASCII CR back to the host computer indicating that it is ready to receive a new command. If
a command returns data, the last byte returned is the task-completed indicator.