Teletype SA110 Checkout And Troubleshooting page 3

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ISS 1, SECTION 578-200-300
Make Incorrect Parity Characters as Explained Below
Note: Space once between each group of 12 letters. Keyboard the characters with incorrect parity as follows:
A - Keyboard A then depress LOC B SP once and keyboard@
U - Keyboard U then depress LOC B SP once and keyboard@
? - Keyboard? then depress LOC
B SP
once and depress space bar
* -
Keyboard " then depress LOC B SP once and keyboard LINE FEED
Figure 2 - Low Speed Parity Error Test Tape Using Parity Keyboard
2.08 Send the parity error tape to the SAU0 receiver
from a local sender, if possible. The response
depends on the SAll0 version being checked, as follows:
(a) The response of an SAU0 AB, SAU0 BA, or
SAll0 CA for either tape should be as follows for
each group of 12 letters: Group 1 - no response; group
2 - two line breaks; group 3 - two line breaks; group 4
- two or three line breaks; and group 5 - three line
breaks. All characters should be printed correctly by the
printer (including incorrect parity
*,
if present in tape).
(b) The response of an SAll0 BB or SA110 CB for
either tape should be as follows for each group of
12 letters: Group 1 - no indication; group 2 - counter
registers 2; group 3 - counter registers 3 more (total is
5); group 4 - counter registers 6 more (total is 11); and
group 5 - counter registers 12 more (total is 23). All
characters should be printed correctly by the printer
(including incorrect parity
*,
if present in tape). Lamp
flashes for each error or lights on first error and blinks
off and on for all following errors until reset by
depressing lamp housing, depending on strapping.
2.09 If any deviation from the correct response occurs
for a local sender, refer to Part 3.
If
a deviation
occurs for a remote sender, repeat the test one or two times
to see if it was caused by line noise. If the same deviation is
repeated, refer to Part 3.
C. Significant Distortion Detection
2.10 Operation of the significant distortion chec.k, if
used, may be checked with a DXD800 signal
distortion test set or equivalent, either remotely or locally. If
a DXD800 is used, set the test knob to R, turn the
INCREASE DISTORTION knob so that about 40 to 45
percent bias distortion, either marking or spacing, is intro-
duced, and check operation of the set. Continuous Rs should
be copied by the printer. Increase the distortion further and
repeat. At some point between 45 and 51 percent distortion,
the printer should stop printing (and spacing) and the SAll0
should indicate continuous errors.
Note: Thi; distortion percentages in 2.10 apply to
local testing only. If testing is done remotely, the
distortion introduced by the transmission lines must be
taken into account.
2.11 If the SA110 garbles characters with less than 45
percent distortion or indicates errors for such
characters, or if it fails to garble characters distorted more
than 51 percent or indicate errors for them, refer to Part 3.
HIGH SPEED EQUIPMENT (DATASPEED Type 2 Sets)
A. Reception of Normal Data
2.12 This test requires transmitting a test message to the
terminal having the SAll0, either locally (at a
send-receive station in the TEST position or over a telephone
extension) or remotely (over transmission lines). If a remote
sender is used, transmission errors may occur which. are not
detectable by the SAU0, or which have only the parity bit
changed and so arc detected by the SAU0 as errors but
appear correctly in the punched tape. The presence of an
error in the tape which was not detected by the SAll0 or the
appearance of an error indication not accompanied by an
error in the tape, then, does not necessarily mean that a
malfunction occurred. Should this happen, testing must be
extended to determine whether other errors
will
be detected
or other false indications occur.
If
a local sender is used, no
transmission errors can occur.
2.13 When a remote sender is used, the data connection
to the terminal should be established in the usual
manner as though the SAl 10 were not there. If there is more
than one remote sender to choose from, pick the sender most
likely to have the lowest overall error rate. This will probably
be a new sender, or one recently readjusted, located in the
same city as the SAU0 receiver or otherwise physically as
close to it as possible. If records have been kept of the error
rates from various senders, select the best one regardless of its
age or location.
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