3-9
Part No. 001-2100-XXX
Mode
Mode allows the user to select the communications mode for the Primary and Secondary COM ports. See Table
3-2 for available modes.
Sync/Esc Framing
A typical Sync/Esc frame resembles the following character stream:
SYNC
ML
Data0
---
DataN
Chksum
8 bits
8 bits
8 bits
---
8 bits
8 bits
with the following definitions made:
Sync (8 bits) - marks the start of a frame when not preceded by an ESC character. When using a Sync/Esc
(Framing) Mode, the Field Programming Software will stuff this character automatically.
ML (8 bits) - the length of the frame. ML is the number of characters left to be received including the checksum
but excluding any ESC characters added as part of the protocol. When using a Sync/Esc (Framing) Mode, the Field
Programming Software will stuff this character automatically based on the number of Data Characters.
Data 0 - N(8 bits each) - frame information
Chksum (8 bits) - the 8 bit 2s complement of the sum of the frame less the SYNC character and any additional
ESC added characters ignoring the carryout of the high order bits. When using a Sync/Esc (Framing) Mode, the
Field Programming Software will stuff this character automatically.
Swap COM Ports
Swap COM Ports allows the user to swap the Primary and Secondary COM ports. For example, if the Primary is
COM1 and the Secondary is COM2, the Primary becomes COM2 and the Secondary becomes COM1 after a Swap
COM Ports is issued. This utility is useful when more than one JSLM2 is connected to a PC since the
programming screens all use the Primary COM port. By issuing a Swap COM Ports, the JSLM2 connected to the
second COM port can be programmed without switching cables.
Table 3-2 Communications Modes
Mode
Description
Sync/Esc with No HS
Send data using the Sync/Esc byte-stuffing protocol with no handshaking
Buffered with No HS
Send buffered data without handshaking
Sync/Esc with RTS/CTS HS
Send data using the Sync/Esc byte-stuffing protocol with RTS/CTS
hardware handshaking
Buffered with RTS/CTS HS
Send buffered data with RTS/CTS hardware handshaking
Sync/Esc with Flow Control HS
Send data using the Sync/Esc byte-stuffing protocol with flow control
handshaking
Buffered with Flow Control HS
Send buffered data with flow control hardware handshaking
