Installation
2–12 1780R-Series Service Manual
Responses from the 1780R-Series SERIAL interface are shown in Table 2–7.
Table 2–7: Serial Remote Responses
Command Description
AThe transmission was successful (ACK)
CCommand not known. (The # character was received, but was not followed by a
U, u, D, d, P, or p.)
DBad data received (all expected data consists of ASCII printable characters).
HBad internal checksum.
NBad transmission checksum (NACK)
TTimed out (the process took too long to complete).
VSoftware version number mismatch.
The rear-panel XY INPUT connector is a 15-pin, sub-miniature, D-type
connector that provides input to the Horizontal and Vertical (X and Y) Amplifi-
ers. They are balanced (differential), DC-coupled, high impedance (>20 kW),
un-terminated inputs provided for audio applications. If AC coupling is desired,
external capacitors are required. These inputs are factory calibrated for 0 dBm in
600 W but can be adjusted for any 600 W system between 0 and 12 dBm. See
Figure. 2–7.
0 dBm is equal to 1 mW or 2.19 V peak-to-peak in 600 W.
12 dBm is equal to 15.8 mW or 8.72 V peak-to-peak in 600 W.
To calibrate the 1780R-Series for a system other than 0 dBm, perform step 38 of
the Adjustment Procedure (Section 6) using a 1 kHz sine wave of the appropriate
amplitude.
Inputs can be driven single-ended by driving either the + or – X and Y inputs
with the opposite polarity inputs grounded.
In addition, a single-ended, high-gain mode can be used for other, primarily
non-audio, applications. It can be accessed by installing plug jumpers on J108
and J205 (on the Vectorscope board, see Table 2–5) and inputting the signal on
the +X and +Y inputs with the –X and –Y inputs grounded.
XY INPUT Connector