Artesyn MVME7616E Transition Module Installation and Use (April 2015) - Manual (Page 33)

Functional Description
MVME7616E Transition Module Installation and Use (6806800A43D) 33
EIA-232-D SIMs employ MC145406 ICs as line transmitters to convert the TTL output signals
from the host VMEmodule to EIA-232-D voltage levels. As line receivers, the MC145406 ICs
convert the EIA-232-D input signals to TTL voltage levels which are sent to the VME module.
The MC145406 transceiver IC requires a series diode on the +12V supply and a clamp diode to
logic ground on the -12V supply. The diodes are located on the transition module rather than
on the SIM due to space limitations.
For all port interfaces, the SIMs support the transmitter signal element timing as either input or
output signals.