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1 – 4
Getting Started
1.2.2
Output
The resulting sum of the enabled input channels appears at the output
BNC connectors on the front and rear panels. Each output connection
is through a 50
Ω
resistor. For normal operation, the user should not
need to terminate the output. If a 50
Ω
termination is applied, note
that the output signal will be divided in half.
If the output signal exceeds
±
10 V, the output overload detection is
activated. This is indicated by the red
OVLD
near the top of the
“OUTPUT” block on the front panel.
1.3
SIM Interface
The primary connection to the SIM980 Summing Amplifier is the
rear-panel DB–15 SIM interface connector. Typically, the SIM980 is
mated to a SIM900 Mainframe via this connection, either through
one of the internal Mainframe slots, or the remote cable interface.
It is also possible to operate the SIM980 directly, without using the
SIM900 Mainframe. This section provides details on the interface.
The SIM980 has no internal protection against reverse polarity, missing
CAUTION
supply, or overvoltage on the power supply pins. Misapplication of power
may cause circuit damage. SRS recommends using the SIM980 together
with the SIM900 Mainframe for most applications.
1.3.1
SIM interface connector
The DB–15 SIM interface connector carries all the power and commu-
nications lines to the instrument. The connector signals are specified
in Table 1.1
1.3.2
Direct interfacing
The SIM980 is intended for operation in the SIM900 Mainframe, but
users may wish to directly interface the module to their own systems
without the use of additional hardware.
The mating connector needed is a standard DB–15 receptacle, such as
Amp part # 747909-2 (or equivalent). Clean, well-regulated supply
voltages of
±
15,
+
5 VDC must be provided, following the pin-out
specified in Table 1.1. Ground must be provided on pins 1 and 8,
with chassis ground on pin 9. The
−
STATUS signal may be monitored
on pin 2 for a low-going TTL-compatible output indicating a status
message.
SIM980
Analog Summing Amplifier