Stanford Research Systems SIM983 Operation And Service Manual page 18

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CAUTION
1.6.2.1 Direct interface cabling
note about grounds
on Pin 2 for a low-going TTL-compatible output indicating a status
message. See Section 3.5 for the description of status messages.
The SIM983 has no internal protection against reverse polarity, missing
supply, or overvoltage on the 5 V and the 15 V power-supply pins. Sup-
ply voltages above 5 5 V on Pin 13, above 16 V on Pin 14, or below 16 V
on Pin 7 are likely to damage the instrument. SRS recommends using the
SIM983 together with the SIM900 Mainframe for most applications.
If the user intends to directly wire the SIM983 independent of the
SIM900 Mainframe, communication is usually possible by directly
connecting the appropriate interface lines from the SIM983 DB–15
plug to the RS–232 serial port of a personal computer.
from the SIM983 directly to RD on the PC, TXD directly to TD, and
similarly RTS RTS and CTS CTS. In other words, a null-modem-
style cable is not needed.
To interface directly to the DB–9 male (DTE) RS–232 port typically
found on contemporary personal computers, a cable must be made
with a female DB–15 socket to mate with the SIM983, and a female
DB–9 socket to mate with the PC's serial port. Separate leads from
the DB–15 need to go to the power supply, making what is sometimes
know as a "hydra" cable. The pin connections are given in Table 1.2.
DB–15 F to SIM983
10
11
7
13
14
1
8
9
Table 1.2: SIM983 direct interface cable pin assignments.
The distinct Ground References 1 and 2, and the chassis ground, are
not directly connected within the SIM983. Ground 1 carries the return
2
Although the serial interface lines on the DB–15 do not satisfy the minimum
voltage levels of the RS–232 standard, these lines are typically compatible with
desktop personal computers.
Name
DB–9 F
3 TxD
2 RxD
5 Computer Ground
to Power Supply
15 V DC
5 V DC
15 V DC
Ground 1 (separate wire to Ground)
Ground 2 (separate wire to Ground)
Chassis Ground (separate wire to Ground)
SIM983 Scaling Amplifier
Getting Started
2
Connect RXD