Hal Communications CWR6850, Инструкция по эксплуатации, Страница: 48 / 64

CHAPTER 6 PAGE 48
Electrical Connection:
All electrical connection points of the CWR6850 have maximum voltage and current ratings as giv-
en in this manual. If these ratings are exceeded for even a short period of time, considerable dam-
age to the terminal may result. Therefore, be very careful KNOW the ratings of the CWR6850 and
the characteristics of any other equipment before making connections. Some common causes of
electrical failures have been found to be:
A. Inadequate grounding, causing RF interference problems as well as sensitivity to AC power line
transients.
B. Damage from lightning, or other transients on the power line or" station antenna system. A
good lightning protection system may help, as will disconnecting the terminal during electrical
storms. However, such things are unpredictable and the CWR6850 is no more susceptible to
such problems than other electronic equipment in the station.
C. Improper connections to high voltage devices or to equipment with inadequate safety grounds.
The CWR6850 does NOT include a high-voltage RTTY loop keying circuit and NONE of its rear
panel jacks should be connected to high voltage loop circuits without the use of isolation devi-
ces such as optical isolators or relays. Be sure that all devices plugged into the AC mains have
safety grounds attached to them. AC line by-pass capacitors in a piece of equipment may
cause the cabinet of that equipment to "float" at an AC potential sufficiently high that damage
might be done to the CWR6850 when the equipment is connected. CONNECT THE GROUNDS
FIRST - THEN CONNECT TO POWER!
6.2 Typical Operational Problems
Because a large number of features are offered in the CHR6850, it is by nature a complicated de-
vice. Therefore, there may be times when it first appears that the terminal has either quit com-
pletely or gone off to "do its own thing". If some of the circuitry has failed, you may well get such
symptoms. However, most often when a new owner finds the terminal "unresponsive", it is actually
doing what it has been instructed to do. Familiarity with the CWR6850 controls will quickly reduce
the chances of "cockpit error" during terminal operation.
The status line and front panel switch position are the best keys to what is happening in the
CWR6850. Often, mistyping one key for another may cause a result entirely different from that in-
tended. Some of the more confusing conditions you may encounter are:
1. Forgetting to terminate the programming of a HERE IS message with the RUB OUT key. If you
forget to end the HERE IS programming, further typed text will continue to be entered into the
HERE IS memory until all 61 memory locations are full. At this point, further typing is not ac-
cepted by the CWR6850 and it appears to be in a non-functioning condition. LOOK AT THE
STATUS LINE! The "W1" next to the reverse video page "3" shows that the terminal is in write
mode for HERE IS 1. Look at the displayed text in HERE IS 1, use the BS key to delete the ex-
tra characters you have typed, and end the HERE IS programming with the RUB OUT key. The
"W1" will now disappear, the original display page will return to the screen, and the CWR6850
will function correctly.
2. The transmit buffer area of the screen will register the presence of a carriage control character
(CR or LF), but will NOT perform the operation on this section of the screen; a LF will not shift
the keyboard entry point to the next displayed line of the transmit buffer. The appropriate
characters will be transmitted, however, in the sequence in which they were entered and the
operations do appear in the RECEIVE section of the screen as they are transmitted (half duplex
operation only). The transmit buffer display area is strictly linear, showing each key typed.
3. When word mode (CTRL-Y) and automatic control (CTRL-A) are used, the transmitter will turn
on and off between words after the pre-typed text has been transmitted. This may cause loss