ICS ELECTRONICS 4863 Manual page 14

1.5.6 RS-485 Basic Protocol
When the Network mode is set to Off, the RS-485 interface operates as does
the RS-232 interface with Echo OFF. All responses messages are terminated
with a linefeed character (LF). A '> LF' prompt is sent after each command
or after the response message. The transmitter is enabled until the prompt
is sent. SRM messages are sent when enabled.
1.5.7 RS-485 Network Address Protocol
When Network Address is enabled, the first two characters of each received
message are checked for an address character that matches the address set
in the unit's Flash memory. If a valid address is detected, then the unit
responds normally to the message. The Address character sequence is an
STX character (02) followed by the address character. The address
character is the ASCII number (0-9 :;<=>?) with a hex value of 30 - 3F. An
example is the IDN query sent to a 2363 at address 4.
i.e. STX 4 * I D N ? (LF)
Prompts are supported when network addressing is enabled. The transmitter
is enabled until the prompt is sent. SRM messages are inhibited when
Network Address is selected
1.5.8 RS-485 Packet Protocol
When Network Packet protocol is enabled, the 2363 always responds to
valid packets sent to it so the user has confirmation the unit received the
message. All message packets include an address character, the command
or query and a checksum. The 2363 responds to packets containing an
address character that matches the address set in its Flash memory. If the
packet checksum and command is valid, the command is executed and an
ACK or response packet is returned. If the checksum or command is
invalid, a NAK response is returned. ACK/NAK command response
packets contain the current ESR Register value.
The general packet format is:
STX Addr Message Characters....ETX Checksum
1-9
1