Microscan MS-5000, User Manual, Page: 46 / 94

Chapter 3 Menu Configuration
3-12
MS-5000 Multidrop Concentrator User’s Manual
3–Ser
ial
Conf
ig.
See Table A-1, “ASCII Table with Control Characters,” on page A-3 for a
complete list of control and display characters.
User Defined Multidrop
Functions exactly the same as User Defined (including the selection of
ASCII characters) except that RS-485 is enabled instead of RS-232 or RS-
422 whenever an address is assigned. It is used when connecting to a host
or other device that does not match standard Multidrop protocol.
Note: Definitions of commands in User Defined and User Defined Multidrop must
be duplicated in host applications to enable poll and select sequences to execute
correctly during transmission. For a list of control characters and display values,
see
Table A-1, “ASCII Table with Control Characters,” on page A-3.
Unlike standard Multidrop, User Defined Multidrop can define an address as
any one character (01 hex to 7E hex) in the ASCII table. The address char-
acter chosen is used as the poll character and the subsequent ASCII char-
acter becomes the select character. For example, if ^A (01 hex) is selected
as the address, the ^B (02 hex) becomes the select address that the host
will use in transmitting host select commands.
Remember, when in User Defined Multidrop:
1. Never assign two consecutive ASCII characters as multidrop
addresses.
2. Never assign the same ASCII character more than once in the protocol.
Like User Defined, User Defined Multidrop is pre-loaded with the characters
of the previously assigned protocol. To acquire most of the standard multi-
drop protocol commands, enable Multidrop first, then select User Defined
Multidrop.
Table 1-5 Protocol Commands
Protocol Commands
Effect
of Command Microscan
mnemonics
ASCII mnemonics
(if different from Microscan)
RES EOT Reset
REQ ENQ Request
STX Start of Text
ETX End of Text
ACK Acknowledge
NAK Negative Acknowledge
EOR End of Record
EOF SOH End of File
XON DC1 Transmitter On
XOFF DC2 Transmitter Off