CANOGA PERKINS 2240 Fiber Optic Modem - Manual (Page 51)

Chapter 4 Data Interfaces
CCITT V.35 (ISO 2593-1993) Model 436
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4.5 CCITT V.35 (ISO 2593-1993) Model 436
This interface complies with CCITT Standard V.35 and ISO 2593-1993. Electrical characteristics
comply with V.35 for clock and data signals and RS-232 levels for control signals.
This interface uses the physical connector type and pinouts specified in ISO 2593-1993 (refer to
Table 4-6). The V.35 interface uses a 34 pin female Winchester connector for the physical
connection.
Note that the table lists the function name shown in ISO 2593 and an aka where applicable. The
rest of this section refers to the ISO 2593 function name and aka interchangeably. For example,
the aka Serial Clock Transmit (SCT) is the same as ISO 2593 Transmitter Signal Element Timing.
The TXD, RXD, SCT, SCR and SCTE pins carry the primary data and clock signals (conforming
to the V.35 standard). In addition, an extra clock signal input is provided to make the 2240/-436
combination more "DTE-like" in tail circuit applications at the clock source end. The remainder of
the pins are either ground references or control signals. Transmit Data (TXD) and Receive Data
(RXD) are the data input and output signals for the modem, respectively.
Serial clock Transmit (SCT) is the modem’s transmit clock reference output that is used for the
internal and slave clock modes. Serial Clock Receive (SCR) is the clock signal for the receive
data unless the 2240's main PCBA W26 (XTCLK) jumper is ON, in which case the Extra Clock
input signal is used to shift receive data out from the 2240. Serial Clock Transmit External
(SCTE) is the transmit clock signal used in either of the External clock modes or when the main
board’s internal CLK/EXT switch is set to EXT (refer to section 3.7).
KG NORM +6V_-6V +6V -6V
KG NORM -6V_GND GND -6V
KG INV +6V_GND GND +6V
KG INV +6V_-6V -6V +6V
KG INV -6V_GND -6V GND
Table 4-6. CCITT V.35 Pinouts
Function Pin (A/B)
CCITT Circuit
Number
Direction
Shield A 101 -
Signal Ground B 102 -
Request to Send (aka RTS) C 105 to modem
Clear to Send (aka CTS) D 106 from modem
Data Set Ready (aka DSR) E 107 from modem
Data Channel Receive Line F 109 from modem
Table 4-5. Settings For the CTS (A) Jumper
CTS (A) KG_OUT KG_SWING
CTS (A) lead
when DTR is
asserted at far
end 2240
CTS (A) lead
when DTR is
negated at far
end 2240