Synchronous Modem Eliminator (SME-4M)
8
3. Installation
Proceed as follows to install the SME-4M:
1. Remove the release screw located on the bottom center of the unit and separate the cover
from the unit.
2. Plug in the cord from the transformer to the male power connector, J3, on the card.
Do not plug the transformer into an AC outlet.
3. Using the cables supplied with your terminal’s or computer’s ports, connect them to the
25-pin connectors (J1 and J2) at the rear of the unit. (If no cables are available, use pin-for-pin
EIA RS-232C cables having at least pins 1-8, 15, 17, 20, 21, 22, and 24 wired (these are the
minimum number of pins that can be connected for the unit to function properly).
4. Select the operating mode by installing the speed selection strap (W2 in Figure 2-3) to async
or the desired synchronous speed as shown below. For more information see
Chapter 7
.
PART NUMBER
SPEED
STRAP POSITION
ME251A-R3,
1200, 2400, 4800
Shown on board
ME251AE-R3,
9600, 19,200 or
ME251C-R3
38,400 bps
ME253A-R2,
56,000 bps
a
ME253AE-R2,
ME253C-R2
ME255A-R2
64,000 bps
a
ME255AE-R2
ME255C-R2
5. For synchronous operation, select the clock source for both DTE devices. For external
clock to be supplied by the device connected to Port A, install the “XA” external clock strap.
For external clock to be supplied by the device connected to Port B, install the “XB”
external clock strap.
6. The following strapping will work in most configurations including IBM
®
System AS/400
™
,
System 36, and System 38:
• CTS A = SW
• CTS Delay = 10 MS
• CTS B = SW
• CD Delay = 10 MS
• CD A = SW
• DSR A = Local
• CD B = SW
• DSR B = Local
Set all front panel pushbuttons in the OUT position.
