Remote Operation - HP 8660C Operating Manual

Model 8660C
Operation
voltages, operator's checks for the modulators are
not included in Table 3-1. Refer to the individual
manuals for the modulator plug-in in use for
applicable operator's checks.
3-27. RF Units
3-28. Many of the tests specified in Table 3-1 do
not apply specifically to an RF Section. Those
checks which are not referred to a specific RF
Section apply equally to the Model 86601, 86602,
and the 86603. When procedures apply to specific
RF Sections only, this information is conveyed
following the procedure.
NOTE
Most of the programming tables in this
section apply equally to local and
remote modes.
3-29. REMOTE OPERATION
3-30. There are currently two means of remotely
programming the Model 8660C. They are BCD
(Binary Coded Decimal) and HP-iB (Hewlett-
Packard Interface Bus). In the text which follows,
programming and other requirements which are
common to both means will be discussed first, then
BCD requirements, and finally HP-IB requirements.
3-31. General Programming Requirements
3-32. There are several conventions which must be
observed when remotely controlling the Model
8660C. Besides providing data with the least
significant digit first, these conventions include:
a. All output levels are referenced to
+13 dBm. This reference operation involves sub¬
tracting 13 from the desired output level.
b. There are three separate modulation
parameters which may be programmed; source,
type and %. Source and type are combined into
one number (source is the least significant digit).
c. When in the remote mode, all front
panel controls except the LINE STBY/ON and FM
CAL controls are inhibited.
d. Digital sweep may not be operated in the
remote mode of operation.
e. When changing from the local to the
remote mode of operation the temporary storage
register should be cleared before a remote entry is
made.
f. The data level inputs to the Model
8660C are as follows: approximately 0 volts (TTL
LOW) = 1 and approximately 2.8V (TTL HIGH) "
0 (sometimes referred to as negative or ground true
logic).
3-33. BCD Remote Operation
3-34. The following information pertaining to
BCD programming, does not apply to HP-IB
programming.
3-35. In BCD remote operation two four-bit paral¬
lel codes are applied to the instrument circuits
through a rear panel connector (J3). These inputs,
if numeric data, are converted to BCD digit serial in¬
formation and clocked into a temporary storage reg¬
ister. If the inputs are address information they are
clocked into a temporary storage register. If the in¬
puts are address information they are used to direct
a clock to strobe the data from the temporary stor¬
age register into the desired final storage register.
3-36. When all of the significant data entries have
been stored in the temporary storage registers, the
least significant digit is stored in a position to allow
it to be the first digit strobed out, then the next
least significant digit, etc, so that the information
will be stored in the appropriate register in the
.same sequence in which it was received.
3-37. Operation of the storage registers not lo¬
cated in the Model 8660C mainframe is detailed in
the manuals for the plug-in sections. Table 3-3
provides examples of programming the registers
which may be programmed when the Model 8660C
mainframe is used.
3-38. Refer to Figures 3-2 and 3-3 for timing
information and to Table 3-5 for interconnection
information.
NOTE
Although it is not necessary to program
frequency first, then modulation (if
any), then attenuation, this sequence
minimizes the time required for entering
data.
3-39. Data Inputs. Data inputs (logic 1=0) must be
referenced to the command pulse as shown in
3-9