Thyracont VD6 - Communication Protocol; Survey of Commands

41
man_vd6s2-de-130515
4.6 Communication Protocol
When the Mini USB port at the back of the VD6 is connected to a PC by a
suitable interface cable (accessory WUSB0002), the instrument can be remote
controlled by the PC via Virtual-Com-Port protocol, e.g. using VacuGraph
TM
Software (accessory VGR).
Communication is carried out according to the Thyracont protocol. The com-
mands are sent as ASCII-code in the following command frame:
Address Code
Data cks CR
Address: 3 Bytes, decimal; address RS232, USB: 001
Code: 1 Byte, command parameter, upper case character for read com-
mand, lower case character for write command
Data: data field, max. 6 Bytes; can be absent depending on code
cks: 1 Byte, checksum, defined as sum over all Bytes of the fields
address, code and data, modulo 64 plus 64.
CR: Carriage Return (0Dh, 13d)
Data Formats:
BOOLEAN 1 Byte
STRING: max. 6 Bytes
UNSIGNED INT: 6 Bytes with leading zeros
FLOAT: 6 Bytes, exponential format
4 Bytes mantissa (means mantissa value x 1000)
2 Bytes exponent, offset 20
FLOAT-values are transmitted in hPa (mbar)!
Example: Value "460019" in a float type data field means 4.6x10
-1
mbar.
4.7 Survey of Commands
By the serial interface of the VD6 the following functions are available:
Command Code Data Type Function
Type T STRING read
Measurement Value M FLOAT read
Setpoint S, s FLOAT read S, write s
(SP1 and SP2)
Hysteresis H, h FLOAT read H, write h
(H1 and H2)
Gas-Correction-Factor C, c UNSIGNED INT read C, write c
Control start/stop A, a BOOLEAN read A, write a
Keylock K, k BOOLEAN read K, write k