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correctly. Therefore, the communication works with an ackowledge protocol using
the standard ASCII bytes ACK and NAK (06H and 15H). This protocol is only active
for communication from computer to RCVDS05.
For communication from RCVDS05 to computer, there is no acknowledgement
available. However there is only communication in this direction after a request is sent
from the computer to the RCVDS05. It is important that when the computer asks the
RCVDS05 for information that it is able to immediately receive the data from the
RCVDS05.
The RCVDS05 returns an ACK byte if it has received the data correctly or a NAK byte
if the received data is not correct. If no RCVDS05 is responding, then no byte is
returned.
Computer to RCVDS05 :
RCVDS05 to computer :
How the RCVDS05 answers
When the computer communicates with the RCVDS05, it is possible that the
computer requests for data from the RCVDS05.
Example :
computer to RCVDS :
STX OFFS ADRo CMDo DAT1o DAT2o DAT3o DAT4o CHKSo
The RCVDS answers ACK
ADR CMD DAT1b DAT2b DAT3b DAT4b CHKSb
With : ADR = ADRo - OFFS
CMD = CMDo - OFFS
CHKSb = (ADR + CMD + DAT1b + DAT2b + DAT3b + DAT4b)MOD256
The RCVDS05 will always return its own address and the received command to the
computer. The computer checks these bytes as an extra control.
No offset is used in the RCVDS-answer.
E.2. The Command Codes.
"Category I" commands
These commands are keyboard or RCU commands.
bytes DAT1, DAT2, DAT3, DAT4 don't care.
60
The RCVDS answers only ACK or NAK
OPERATING INSTRUCTIONS
Record (9
bytes)
R5975765 RCVDS05 020997
ACK or
NAK
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