5.9 ASYNCHRONOUS SERIAL DATA FORMAT
The DATA WORD consists of one ASCII character, i.e., two hexadecimal characters plus one start bit and two stop
bits. The number of incoming stop bits is not critical. The controller can accept any number of stop bits. The controller
will always respond with two stop bits. The MSB of the data bits is the parity bit. When parity is not used the MSB must
5.10 DATA PROTOCOL
The controller is always the passive listener in this protocol. Transmission is always initiated by the host computer. The
host sends a command or a command and data to the controller. The controller responds within 100 ms. either with
system status or with system status and data.
The COMMAND sent by the host must be all upper case letters in the following format except that CKSUM is optional
with the host. The controller will ignore a lack of CKSUM if none is provided by the host computer. The controller will
always respond with a CKSUM even if it is not used. See Examples 5.16 and 5.17. The controller will not accept lower
TO READ DATA:
* UNIT# : R PARAMETER : CKSUM CR
TO WRITE DATA:
* UNIT# : W PARAMETER / DATA : CKSUM CR
Note: The Controller will ignore LF if transmitted after CR.
The Controller will respond within 100 ms. in the following format:
RESPONSE TO READ COMMAND:
$ STATUS : DATA : CKSUM CR LF
RESPONSE TO WRITE COMMAND:
$ STATUS :: CKSUM CR LF
Note: Spacing is included above purely for clarity. Actual data transmission must not include spacings.
NULL characters HEX "09" may be sent within the context of the message to the host from the controller and
should be ignored, but must not be sent to the controller.
ECLIPSE INSTRUMENTATION DIVISION