Connecting to the Host

ASCII  Async

SNA-SDLC (RS232)

Pin

Signal

DCE

DCE

DTE

1

Protect Ground

Connected to the HSM chassis

2

TX Data

To HSM

To HSM

From HSM

3

RX Data

From HSM

From HSM

To HSM

4

RTS (Request To Send)

To HSM (ignored)

To HSM (ignored)

From HSM
(asserted if ready)

5

CTS
(Clear To Send)

From HSM
(always asserted)

From HSM
(always asserted)

To HSM  (accepted)

6

DSR
(Data Set Ready)

From HSM
(always asserted)

From HSM
(always asserted)

To HSM (ignored)

7

Signal Ground

8

DCD
(Data Carrier Detect)

From HSM
(always asserted)

From HSM
(always asserted)

To HSM  (accepted)

15

TX Clock
(DCE Source)

16 x Baud from HSM

At Baud from HSM

At Baud to HSM

17

RX Clock
(DCE Source)

16 x Baud from HSM

At Baud from HSM

At Baud to HSM

20

DTR (Data Terminal Ready)

To HSM (ignored)

From HSM
(always asserted)

From HSM
(always asserted)

23

Data Rate Select

Not connected

Not connected

Not connected

24

TX Clock

To HSM (Ignored)

To HSM (ignored)

Pin

Signal

Details

A

Protective Ground

Connected to the HSM chassis.

B

Signal Ground

Connected to the HSM Chassis.

DCE

DTE

C

RTS (Request To Send)

Input (ignored)

Output (asserted if HSM has data to send)

D

CTS (Clear To Send)

Output (always asserted)

Input (required for HSM to send data)

E

DSR (Data Set Ready)

Output (always asserted)

Input (ignored)

F

RLSD (equivalent to DCD)

(Rx  Line Signal Detect)

Output (always asserted)

Input (ignored)

P

TxD (A) (Transmit Data)

Input

Output

S

TxD (B)

R

RxD (A) (Receive Data)

Output

Input

T

RxD (B)

Y

TxCk (A) (Transmit Clock)

Output (at Baud)

Input (at Baud)

AA

TxCk (B)

V

RxCk (A) (Receive Clock)

Output (at Baud)

Input (at Baud)

X

RxCk (B)

U

DTE TxCk (A) (Tx Clock)

Input (at Baud)  (not used)

Output (at Baud)

W

DTE TxCk (B)