
DESCRIPTION AND OPERATION
2 - 10
I-E96-217A
®
jumpers if using software that requires the SPM to monitor the
RTS signal.
NOTE: In the continuous enable position, the RTS line is not physi-
cally disconnected from the faceplate connector, but is disconnected
from P3. When connecting equipment to the faceplate connector,
these lines must not be grounded or forced to other voltage levels.
Pin 5
CLEAR TO SEND (CTS) - DTE input signal line that a DCE uses
to signal a DTE in response to a received RTS signal.
Since the SPM does not use the RTS signal, it generates the
CTS signal while the MFT is in its normal state and the ACIA is
initialized. For Bailey Controls software, this line must be con-
tinuously enabled. Jumpers (JP11 and JP12) tie the line to +15
VDC to continuously enable the output. The jumpers can also
be set to provide a logic 1 output if required.
Pin 6
DATA SET READY (DSR) - DTE input signal line that a DCE
uses to signal the DTE that the requested data is ready to be
sent.
For the SPM, this signal is synonymous with the CTS signal
because of an overlap in SPM signal definition. Both signals
are generated at a common point. The Bailey Controls software
requirements are the same as for the CTS signal.
Pin 7
SIGNAL GROUND (SIG GND) - This is a common line for all
signals.
Pin 8
RECEIVED LINE SIGNAL DETECT (RLSD) - DTE input signal
line that indicates that a valid communication link has been
established between the DTE and DCE.
For the SPM, this signal indicates when access to the module
bus is possible. The communication link is valid if the ACIA is
enabled and the MFT is in its normal state. This signal is syn-
onymous with the CTS and DSR signals. All three are gener-
ated from a common point. It is generated to allow interfacing
with other data equipment. The Bailey Controls software
requirements are the same as for the CTS signal.
Pin 20
DATA TERMINAL READY (DTR) - DTE output signal line that
the DCE uses to confirm that the DTE is present, and the com-
munication link is to be maintained.
This signal has the same purpose for the SPM. If the DTE device
does not generate this signal, jumpers on the SPM can be set to
continuously enable the input by tying the line to +15 VDC.
NOTE: In the continuous enable position, the DTR line is not physi-
cally disconnected from the faceplate connector but is disconnected
from P3. When connecting equipment to the faceplate connector,
these lines must not be grounded or forced to other voltage levels.