R&S ZVL
Remote Control
Status Reporting System
Operating Manual 1303.6580.32-05
335
Structure of an SCPI Status Register
Each standard SCPI register consists of 5 parts which each have a width of 16 bits and have different
functions. The individual bits are independent of each other, i.e. each hardware status is assigned a bit
number which is valid for all five parts. Bit 15 (the most significant bit) is set to zero for all parts. Thus the
contents of the register parts can be processed by the controller as positive integer.
Description of the five status register parts
The five parts of an SCPI register have different properties and function:
CONDition
The CONDition part is permanently overwritten by the hardware or the sum bit of the next lower
register. Its contents always reflect the current instrument state.
This register part can only be read, but not overwritten or cleared. Reading the CONDition register
is nondestructive.
PTRansition
The two transition register parts define which state transition of the condition part (none, 0 to 1, 1
to 0 or both) is stored in the EVENt part.
The Positive TRansition part acts as a transition filter. When a bit of the CONDition part is
changed from 0 to 1, the associated PTR bit decides whether the EVENt bit is set to 1:
PTR bit =1: the EVENt bit is set.
PTR bit =0: the EVENt bit is not set.
This status register part can be overwritten and read at will. Reading the PTRansition register is
nondestructive.
NTRansition
The Negative TRansition part also acts as a transition filter. When a bit of the CONDition part is
changed from 1 to 0, the associated NTR bit decides whether the EVENt bit is set to 1.
NTR bit =1: the EVENt bit is set.
