HP 1000 Programming Manual

HP 59307A
VHF Switch
Device Introduction
The HP 59307At provides two DC to
switches (4 pole single throw) which are optimized for fast
rise time (one nanosecond)
switches can be controlled either manually from front-panel
push buttons or remotely from the HP-IB.
Under program control, the switches are operated by ad-
dressing the 59307A to listen, and then sending either the
ASCII character A or B followed by the switch number (1
through 4). This causes the common switch
or switch B to be connected to the selected
bcal RESET push button lets the operator assume front-
panel control of the instrument
has not been applied to the 59307k
The VHF switch is a listen-only device. Data messages may
be sent to the device to select input channels, bun the device
is not capable of retuming messages to the computer,
Addressing
Setting the 59307 A address is straightforward. The rear
panel can be seen in figure 2-1. Viewed from the back, when
the box is rotated onto its left side,
in binaryu Address 25B is set at the factory. As an aid tor
address setting, the switches
underside of the box.
System Preparations
Lu Assignment
One LU will needed for the 59307A. The File Manager
command,
will assign LU 22 to EQT 10, The device address of the
59307A witl be 25 octal.
'The 59307A VHF Switch Operating and Service Manual (part
number, 59307-90001) contains complete ntormation
the instrument. This mte should also be used in conjunctøn
Applzatøn Note 401-1 (5953-2800).
HP-lß
Programming Guide
MHz, 50 ohm
pulse waveforms. These
for switch A
switch position. A
if a local bckout command
the switches can be read
are also described on the
to
with
HP 1000
Computer
Output Buffering
Tum off buffering, until the devte is checked out From File
Manager,
will unbuffer EQT 10. Note that if switch timing is critical, the
buffering option may cause timing problems and should be
left off,
Time-out
Time-out is an error condition
time-out errors may be optionally evaluated by the operating
system or the user's program by setting the device configura-
tion word. The 59307A will cause a time-out to occur only if
the hardware malfunctions, the listen address is set impro-
or the bus is inoperative,
Because operator intervention is usually required to correct
these problems, one alternative is to let the operating system
process the time-out (i.e„ set the 59307A down) when it
wcurs, The device configuration word defaults to operating
system error processing,
The user program can process time-out errors wt'En the E bit
of the configuration word is set to one (see figure 2-2). The
procedure in this case is to call the subroutine "IBERR" after
eæh 1/0 request. 2
2See the HP-18 1-Sers Manual (pan no. 59310-90064) for tmre
information, Appendix C ot that manual
(59310-60011) containmg IBERR, RMOTE, and LOCAL
HEWLETT PACKARD
Application Note 401-2
acaz
for this device. Remember
describes %MESS
that