SECTION 4
OPERATION
Pacific Power Source ©2013
4-32
Document # 126050-10 Rev E
4.6.2 J3 AND J4 SERIAL I/O
This paragraph describes the Serial Ports available on the MS-Series Power
Source.
The MS Series Power Source is provided with Dual Serial Communication Ports
designated COM A and COM B. These output are RS-232-C Ports with bi-
directional logic. Power Source status is stored in an internal register and
transmitted through these ports when interrogated.
PHYSICAL CONFIGURATION
Refer to Figure 4.6. J3, or COM A, is a female, DB-25 socket. This socket is a
Data Communications Equipment (DCE) Port configured to be interfaced with a
Data Terminal Equipment (DTE) device such as a "dumb" terminal, or PC set up
as a DTE.
J4, or COM B, is a DTE port configured to be interfaced with a DCE device such
as a modem. A female, DB-25 socket is also provided for this port.
BAUD RATE
The Baud Rates for data transmission are 300, 1200, 2400 or 9600 as selected
by switch S41 on the Display PCB Assembly. (Refer to Figure 4.5.1.)
COMMUNICATION DATA FORMAT
Data is transferred as an 8 bit word with 1 Start,
1 Stop, and no Parity bit.
DATA TRANSMISSION
Serial Port design is such that no "Handshaking" is required in hardware or
software. Due to this fact, data transmitted to the MS must be limited to 5
characters per second. Data bursts are sent from the MS in approximately
200ms increments.
Refer to Table 4.6.2. Hardware handshaking signals, (i.e. TXDA, CTSA, DCDA,
etc) are provided for operator convenience. The MS requires only 3 lines:
Receive, Transmit and Ground.
