1
These may be signed or unsigned words depending on the AQ setting on the RIO-4712x. For example, if the bytes
received from the data record packet for analog input 0 were 00 80, it could have the following meaning, depending on
AQ
Little Endian
AQ 0,1
AQ 0,2
AQ 0,3
AQ 0,4
80 00
-5 Volts
-10 Volts
2.5 Volts
5 Volts
This data can be broken up into sections. The
Data Record Map
includes the 4 bytes of header. The
General Data Block
consists of the sample number, the error code, and the general status.
The I/O
Data Block
includes all the other items in the above table.
Explanation of Status Information
Header Information –
Bytes 0, 1 of Header:
The first two bytes of the data record provide the header information.
BIT 15
BIT 14
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
1
N/A
N/A
N/A
N/A
N/A
N/A
N/A
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Bytes 2, 3 of Header:
Bytes 2 and 3 make up a word, which represents the Number of bytes in the data record, including
the header. Byte 2 is the low byte, and byte 3 is the high byte.
Note:
The header information of the data records is formatted in little endian.
General Status Information (1 Byte)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Program
Running
N/A
N/A
N/A
N/A
Waiting for
input from IN
command
Trace On
Echo On
ZC and ZD Commands
Another important feature of the data record is that it contains two variables that can be set by the
user. The ZC and ZD commands are responsible for these variables. Each variable can be a number, a
mathematical equation, or a string. See the Command Reference for more information on the ZC and
ZD commands.
Chapter 3 Communication ▫ 40 RIO-47xxx Rev. 1.0r