2116 Erratic Behavior

[johnsfine]

what would
cause the remote to behave better after reversing a battery?

The components in a 4 battery remote are pretty much the same as the components in a 2 battery remote. Those same components work at around 3 volts in the 2 battery models and at around 6 volts in the 4 battery models.

If the printer port voltage is too low, it can't communicate with a remote using 6 volts but can communicate with one using 3 volts.

If you put just two batteries in a 4 battery remote, there's no connection (unless you kludge something) so you have zero volts. But four 1.5 volt batteries one of which is backwards gives you the 3 volts you want.

[Capn Trips]

what would
cause the remote to behave better after reversing a battery?
Does it cause a momentary reverse current flow (until the
reversed battery's potential equals that of the rest of the
system) that discharges a component on the board?

Eric

The experts can certainly chime in here with more details, but reverse current flow is NOT the issue.

My elementary understanding of electricity tells me that 4 1.5 volt batteries in series yield a 6 volt potential powering the remote under normal circumstances. Internal to the remote, there is circuitry that does "something" to that voltage to establish the correct operating voltages for each of the components within the remote, including keeping the EEPROM out of a "reset" condition. (Hence the "reset" every time you change the batteries, as that "holding" voltage is removed).

The JP1 interface, via the parallel port, when it tries to speak to the EEPROM, has to send some measurable voltage to the EEPROM. If that voltage is insufficient to overcome the "holding" voltage (if you will - I'm making up terminology, 'cause I'm in WAY over my head here ), then you get failed interface checks, etc. Apparently, each computer's parallel port has some minute variability in that voltage, such that there is no "Universal" combination of batteries, interface types, etc that will always GUARANTEE successful communication.

I tried up/downloading with a battery REMOVED, but got no communication either, so an open-circuited power supply was not an option. My combination of equipments require a completed circuit through the remote's power supply circuitry, but not too high a voltage. When I saw that - in MY particular circumstance - using a couple of DEAD batteries gave me greater success, I concluded that rather than keeping a segregated set of dead batteries lying around just for JP1 use, that would invariably get lost or mixed up with something, I could get the same net result - reducing the remote's supply voltage, by simply reversing a battery . Nothing more complex or insidious.

Bottom line: The only effect on the remote of reversing a battery is that the SUPPLY voltage is reduced from 6 to 3 - and in MY particular combination of computer, port, interface and remote - it works.

P.S. All of the above only applies to my RS 15-2117. My RS 15-1994's all work fine with any state of charged batteries and I have been uploading/downloading for two years, now.

[ek2116]

All:

FYI, I'm having the same problem with my 8810.
Since the probability of both remotes having the
same problem is essentially nil, I have concluded
that it's my PC.

I will live with the problem.

Thanks for all your comments.

Eric