FDI2056 Use
r’s Manual
v 2.0 r 1.1
– 03/13
Copyright © 2013 Metrolab Technology SA
51
www.metrolab.com
4-10 THE PDI 5025 STATUS REGISTERS
The PDI 5025 has seven internal status registers that can be accessed by the
user. These registers can be used to interrogate the instrument about its current
state. Each status register contains eight bits and can be read by the host
computer in two different formats, in either hexadecimal or binary. The registers
are numbered 1 to 7.
To read a status register, the host computer must send either of the commands
shown below:
STH,n
Where n (n=1 to 7) is the number associated with the status
register. If n is omitted then the value of 1 is assumed. This
command generates a two character reply representing the value
of the status register in
hexadecimal
.
STB,n
Where n (n=1 to 7) is the number associated with the status
register. If n is omitted then the value of 1 is assumed. This
command generates an eight character reply (0 or 1) representing
the value of the status register in
binary
. The first character in the
string corresponds to the most significant bit of the status register
and the eighth character to the least significant bit.
The detail of the seven status registers is given in the following tables.
STATUS 1
Measurement Status (1 Byte)
This status byte is cleared as soon as it has been read except for
bit 7, which is only cleared once
STATUS
2 has been read.
Bit 7
Status 2 Flag
This bit is set to indicate that
STATUS
2 is not zero and that it should be
read.
Bit 6
This bit is always read as 0.
Bit 5
Command Error
This bit is set each time that a command sent by the host is not
syntactically correct, either because the mnemonic is unknown or
because one or more values are incorrect. This error is also generated
when a command is issued at a time when it is not appropriate.
Bit 4
Over-range Error
This bit is set each time the input voltage of any channel reaches the
positive or negative over-range threshold.
Note:
An over-range error has no effects before the first trigger