| |
M1BYT > TECH 23.03.05 19:31l 43 Lines 1860 Bytes #999 (0) @ WW
BID : FF3486M1BYT
Read: GUEST
Subj: Re: volt readings
Path: DB0FHN<DB0THA<DB0ERF<DB0HGW<ON0DXC<WA7V<EB4BCS<ED1ZAC<CX2SA<GB7YFS<
GB7FCR
Sent: 050323/1656Z @:GB7FCR.#16.GBR.EU #:40113 [Blackpool] FBB-7.03a $:FF3486M1
From: M1BYT@GB7FCR.#16.GBR.EU
To : TECH@WW
N2JXN Opined with considerable skill:-
> Hello looking for som info. Building a rs232 to ttl interface and need to
> measure a - voltage. What
> would be the prefured meathod fo doing this
Not quite sure what you mean by that question?
If you want to measure the static voltage, then an ordinary voltmeter would be
adequate. If you want to measure the dynamic voltage, then an oscilloscope
would be the instrument of choice.
You could in fact roughly check the TTL levels with a simple TTL logic probe.
The TTL voltages levels (from memory) should be a minimum of 4.2v for a logic
high and a maximum of 0.7v for a logic low. The TTL level equivalent of RS232
is (I think) known as RS423 spec..
For the RS232 side of the interface you could again use a voltmeter for static
measurements, a scope for watching the dynamic voltages, but instead of a
logic probe you would use a little gadget (name forgotten) which indicates the
highs and lows of each pin via LED's.
Minimum voltage for high on RS232 (again from memory) would be +7 to +12v and
for low -7 to -12v.
ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ»
º 73 from Harry, M1BYT @ GB7FCR.#16.GBR.EU º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º International Museums Weekend 18th+19th June 2005 º
º www.ukradioamateur.org/imw/index.html º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º The ARC's FL/RAE courses + Newcomers Introduction º
º to amateur radio:- http://www.ukradioamateur.org/ º
ÌÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍËÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ͹
º QTH: Garforth, W. Yorks.. º Timed 15:40 º
º harry.m1byt@tiscali.co.uk º 23 Mar 05 º
ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÊÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ
Message sent using WinPack-Telnet V6.80
Read previous mail | Read next mail
| |
