38
AT824/825/826 Handheld LCR Meter
uint nChecksum; //Checksum 4bytes
} TUSB_CMD;
#define program pack()
Here,
cSize:
60
nSignature: 0x88805550
sCmd,sPara: reference at SCPI set
nChecksum:
32 checksum
A complete send command pack(from PC) as follows:
cSize:
0x0000003C,
sHeader: IDN?
sPara:
(blank)
nSignature:
0x88805550
nChecksum: 0x00002BC1
As command pack format and number of bits are fixed, so command
words and parameters which are not qualified with the specified number
of bytes must be filled hexadecimal. HEX: 0x00.
Table 8-1 A complete command pack in Hex format.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
00 00 00 40 49 44 4E 3F
00 00 00 00 00 00 00 00
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
00 00 00 00 00 00 00 00 88 80 55 50 00 00 2B C1
Instrument response pack is 64 bytes, not sufficient for 0x00 fill out. (Not
ASCII “0”)
A response pack (from instrument):
ASCII format:
AT826, REV A1.0, 00000000, Applent Instruments Inc.
To test instrument USB-HID, we have free “Applent HID communication
tester” software, you can download from:
8.3.2
Notation Conventions and Definitions
A definition is not a part of a command, just used in interpretation and is
not included in transfer.
The following conventions and definitions are used in this chapter to
describe USB-HID operation