Direct Interfacing - Stanford Research Systems SIM984 Operation And Service Manual

1.3 SIM Interface

1.3.2 Direct interfacing

1.3.2.1 Direct interface cabling
1.3.2.2 Serial settings
SIM984 Isolation Amplifier
The SIM984 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 sup-
ply voltages of ±15,+5 and +24 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.
If the user intends to directly wire the SIM984 independent of the
SIM900 Mainframe, communication is usually possible by directly
connecting the appropriate interface lines from the SIM984 DB–15
plug to the RS-232 serial port of a personal computer.
from the SIM984 directly to RD on the PC, TXD directly to TD. 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 personal computers, a cable must be made with a female
DB–15 socket to mate with the SIM984, 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.
The initial serial port settings at power-on are: 9600 Baud, 8–bits,
no parity, 1 stop bit, and no flow control. The serial baud rate and
word size are fixed, but the parity may be changed with the PARI
command.
1
Although the serial interface lines on the DB-15 do not satisfy the minimum
voltage levels of the RS-232 standard, they are typically compatible with desktop
personal computers
1 – 5
1
Connect RXD