About EFTPOS

[JJ]

Hello.

I would like to know some informations about how EFTPOS terminals work
and communicate.

For example, what protocols are used (their names so that I can Google
for them)?
I've read about ISO-8583, Open Payment Initiative and AS-2805, but none
looks like being the one that is used in the systems that I am trying to
study. I noticed that in all the messages the first 2 bytes represent
the message length in Binary-Coded Decimal. I know ISO-8583 uses BCD
extensively, but the rest of the messages just don't fit to the
specification.

Another thing that I would like to know is the following one. Can an
EFTPOS terminal have merchant-developed applications installed on it?
For example, I know that a smartcard can have some special applications
that provide aditional functionallity as a plugin; I'm asking if EFTPOS
terminals allow anything similar to this.

An most importantly, can they affect the way the device communicates
(i.e. can they affect the workings of the protocol, even if only
creating new message opcodes, etc)?

In case this can help I can tell you that I'm dealing with terminals
from the Ingenico manufacturer.

Thanks!
JJ

[JJ]

Post by JJ
An most importantly, can they affect the way the device communicates
(i.e. can they affect the workings of the protocol, even if only
creating new message opcodes, etc)?

I mean, can *the applications* affect (......) ?