Sensoray 2600 User Manual

Page 27

2600 Family Instruction Manual

Chapter 4 : Serial Communication Server

Figure 30: Attributes Byte

PHY

These two bits specify the physical layer type and
behavior as follows:

Notes

1. PHY values 10 and 11 are available only on model 2601

Revision D (or later) circuit boards.

PHY=00

: Full-duplex RS-232.

PHY=01

: Full-duplex RS-422. Both receiver

and transmit line driver are enabled at all times.

PHY=10

: Half-duplex RS-422 or RS-485. The

transmit line driver is enabled only while
characters are being sent; it is automatically
disabled (tri-stated) when the transmitter is idle.
The receiver is enabled only when the transmitter
is idle, so that receive characters are blocked
while the transmitter is active. The receiver
turn-around time is 250 microseconds,
maximum.

PHY=11

: Full-duplex RS-422 or RS-485. The

transmit line driver is enabled only while
characters are being sent; it is automatically
disabled (tri-stated) when the transmitter is idle.
The receiver is enabled at all times. This mode
can be useful for multi-master RS-485 device
networks that require collision detection. The
receiver turn-around time is 250 microseconds,
maximum.

Refer to Section 4.2.2 for information about how
to configure PHY for various device network
topologies.

FLOW

This bit enables XON/XOFF flow control. See
Section 4.1.1 for information about flow control.

PAR

These two bits specify whether even, odd, or no
parity will be applied to transmitted and received
characters. When even or odd parity is enabled,
all incoming characters are parity checked and
any parity errors will be detected and reported.

STOP

This bit specifies the number of stop bits to send
when transmitting a character.

DAT

These two bits specify the number of data bits to
be used in both transmitted and received
characters.

4.4.1.3 LED Behavior

The LEDs byte is shown in Figure 31. When set
to logic one, each bit will cause the com port’s
status LED to light for approximately 100
milliseconds in response to the associated event.

Any combination of these bits may be specified.
For example, the XMT and RCV bits may both be
set, in which case the LED will light when a
character is sent or received at the com port.

After a module reset, the RCV flag is set and all
other flags are reset to zero.

Figure 31: LEDs Byte

XMT

causes the LED to light when a character is

transmitted.

RCV

causes the LED to light when a character is

received.

ERR

causes the LED to light when a receiver

break condition is detected or when an error
(framing, overrun or parity) is detected.

Response

(Status)

Notes

The target com port must be closed when this
command is issued. If the com port is open, the
command will be rejected and the returned status
byte’s REJ flag will be set.

PHY

Duplex

Type

Tx Enabled

Full

RS-232

Always

Full

RS-422

Always

Half

RS-422 / RS-485

When

Sending

Full

FLOW

PAR0

STOP

DAT1 DAT0

PAR1

00 = 5 bits

Char Size

01 = 6 bits

10 = 7 bits

11 = 8 bits

X0 = None

Parity

01 = Odd

11 = Even

0 = 1 bit

Stop Bit Length (in bit times)

1 = 1.5 bits (char size 5)

1 = 2 bits (char sizes 6,7,8)

XON/XOFF

00 = RS232

Physical Layer

01 = RS422, Tx always on

Flow Control

PHY1 PHY0

10 = RS485
11 = RS422, idle 3-state

0 = Disabled

1 = Enabled

Parameter

Function

Status

Com port status. The REJ bit flag
will be set if the com port is open.

XMT

RCV ERR