Error Handling - Masterflex L/S 7523-60 Manual De Operación

1.9 - SATELLITE RESPONSE
When the pump satellite correctly receives a
command, it will send back an <ACK> (06 hex) if it
was not an all pumps command (P99). If data has to
be sent back to the master in response to the
command, it will be sent as shown in Table 2. If the
satellite detected an error while receiving a
command, it will respond with a <NAK>.

1.10 - ERROR HANDLING

Depending on the error code received from the
satellite, the control computer would have to take
appropriate action to try to eliminate the error
condition. Communication errors of type 1, 2 or 3
indicate a hardware type error: noisy
communication lines, bad connection, glitches or
circuit failure. Communication error codes 4 or 5
could be hardware errors as previously described or
software errors caused by incorrect commands or
data being sent by the control computer. For
hardware type errors the control computer would try
sending the same command to see if the problem
was only momentary. If an error code is returned
four times in a row or if there is no response at all,
the control computer would abort trying to send the
command and notify the operator of the type of
error.
If a satellite does not respond at all, the control
computer can assume one of the following:
1. If all other satellites connected after the satellite
in question also don't respond, the
communication link is broken at that point or the
satellite is defective.
2. If all other satellites respond, the unresponding
satellite is either turned off, removed from the
loop, or defective.
COMMAND CHARACTERS FROM CONTROL
A Request auxiliary input status
B Control auxiliary outputs when G command executed
C Request cumulative revolution counter
E Request revolutions to go
G Go Turn pump on and auxiliary output if preset
H Halt (turn pump off)
I Request status data
K Request front panel switch pressed since last K command
L Enable local operation
O Control auxiliary outputs immediately without affecting drive
R Enable remote operation
S Set motor direction and RPM
S Request motor direction & RPM
U Change satellite number
V Set number of revolutions to run
Z Zero revolutions to go counter
Z Zero cumulative revolutions
<CAN> Terminates line of data up to and including STX (used primarily for keyboard input)
<ENQ> Enquire which satellite has activated its RTS line
1.11 - SATELLITE REQUEST TO
SEND
When a satellite wants to communicate with the
control computer, it will turn on its request to send
(RTS) line and then wait for the (ENQ) enquire
character (05 hex) from the control computer. The
following list shows the possible conditions that
would cause the pump drive to activate its RTS line.
1. Auxiliary input status change.
2. Motor error.
3. Stop key pressed at satellite while in the remote
mode.
4. Programmed volume was reached.
5. Power up.
The following is the sequence of events for when
RTS is activated by a pump drive:
1. Satellite enables RTS line.
2. When control computer detects RTS, it will
transmit the (ENQ) enquire command (05 hex)
after it completes any communications it may be
in the process of doing.
3. When the satellite that has its RTS line enabled
receives the <ENQ> it will disable its RS-232C
buffers to block the other satellites below it in the
daisy-chain from communicating with the control
computer. This would give the satellite closest to
the control computer the highest priority if more
than one satellite enabled its RTS line at the same
time.
4. Next the pump drive will send the response from
the I command as shown in section 1.8.
5. If the control computer received the satellite
response without any errors (parity, overrun etc.)
COMPUTER TO PUMP
Table 1 - Pump satellite commands
6. If more than one satellite has its RTS line
7. If a satellite was responding to an enquire
none
xy, x = aux1, y = aux2, 0 = off, 1 = on
none
none
none = run for number of revolutions set by V command
0 = continuous run until Halt command
none
none
none
none
xy, x = aux1, y = aux2, 0 = off, 1 = on
none
+xxx.x, -xxx.x, +xxxx, -xxxx
+ = CW, –=CCW
none
nn
new satellite number
xxxxx.xx
none
0
none
none
13
it will send an acknowledge <ACK>Pnn<CR>
which will cause the satellite to release its RTS
line and enable the RS-232C buffers allowing the
satellites below it in the daisy-chain to
communicate. If the control computer detected
any error during the transmission it would send
the enquire (ENQ) again which would cause the
satellite to re-send its response. The control
computer will retry a maximum of four times
before aborting and reporting the error to the
operator.
enabled, the control computer would see only the
response from the satellite closest to it. After the
closest satellite sent its response and released the
RTS line, the control computer would see the
RTS of the other satellite and again issue the
enquire command which would allow the next
satellite with RTS active to respond.
command and another satellite with higher
priority also started to respond, cutting off the
first responding satellite, the control computer
would receive invalid data and get some type of
error (parity or framing). This would cause the
control computer to resend the enquire, but this
time only the higher priority satellite would
respond since the communications with the lower
satellites is blocked.
PARAMETER FIELD