Filter
Top Products
Serial I/O: Serial Connector Pin Assignments
10002367-02 PmT1 and PmE1 User’s Manual
5-7
Note: The EIA-232C specification defines a maximum rate of 20,000 bits per second over a typical 50-foot cable
(2,500 picofarads maximum load capacitance). Higher baud rates are possible, but successful operation
depends specifically upon the application, cable length, and overall signal quality.
The formula for the synchronous baud rate is:
sync baud rate = (system frequency) ÷ ((clock divider +1) x (Div16))
The clock divider value is stored in bits (12:1) of the BRGC. The Div16 value (1 or 16) is
selected with bit 0 of the BRGC.
Ta ble 5 - 5 lists the clock divider and Div16 values associated
with typical synchronous baud rates.
Table 5-5: Synchronous Baud Rates
SERIAL CONNECTOR PIN ASSIGNMENTS
The PmT1 and PmE1 module has a 64-pin connector for the serial I/O interface. The P14 pin
assignments, including the VME P0 and VME P2 pin numbers specific to Emerson base-
boards are shown in
Tab le 5 -6 .
Note: The VME P2 pin numbers are listed for a module installed in expansion site J1x. The VME P0 pin numbers are
listed for a module installed in expansion site J2x.
Reference “PMC Connector Pin Assignments” Section for the remaining PMC connectors,
P11 and P12; and “Front Panel I/O” Section for the front panel I/O connectors, P1 and P2.
Table 5-6: P14, P0, P2 Pin Assignments
76800 1 33 75757.6 1.4
System Frequency=40 MHz
Baud
Rate
(Kbaud):
Div16
Value: Clock Divider + 1: Actual Frequency:
Frequency Error
(%):
1544 (T1) 1 26 1538.5 0.4
2048 (E1) 1 20 2000 2.3
P14 Pin: P0 Pin: P2 Pin: Signal: P14 Pin: P0 Pin: P2 Pin: Signal:
1E4C1Console RxData2———
3 C4C2Console TxData4 — — —
5 ——— 6———
7D5C4GND 8C5A4Download RxData
9 — — — 10 A5 A5 Download TxData
11 ——— 12———
System Frequency=40 MHz (continued)
Baud
Rate:
Div16
Value: Clock Divider + 1: Actual Frequency:
Frequency Error
(%):