Serial Output; Analog (4-20 Ma) Outputs And Communications (Pl5 - Green); Alarm Relay Contacts (Pl1- Black) - Michell Instruments XTC601 User Manual

INSTALLATION
4.5.4

Serial Output

The analyzer has Modbus RTU communications over RS485 protocol; please see
Application Software CD for more details.
• Type: Modbus RTU over RS485
• RS485: 2 wire (plus ground), half duplex
• Baud Rate: 9600
• Parity: None
• Data bits: 8
• Stop bits: 1
4.5.5

Analog (4-20 mA) Outputs and Communications (PL5 - Green)

PIN 7
RS485
GND
NOTE 1: Channel 1 is fixed range output over instrument range and Channel
2 is adjustable within instrument range.
NOTE 2: For long cable lengths, a termination resistor of 120Ω is provided to
aid in impedance matching of the communications cable. This is selectable
via JMP3. A terminating resistor is simply a resistor placed at the extreme
end or ends of a cable on an RS485 network to reduce effects of impedance
mismatch. Impedance mismatch can cause reflections of data as it passes
down the cable and the reflections could be large enough to cause data errors.
4.5.6

Alarm Relay Contacts (PL1- Black)

PIN 6
Hi Alarm
C
• Type: SPCO (NO, NC and C)
• Contact Rating, Max: 5 A, 250 V
• Hysteresis is 0.03%
• AL1 and AL2 can be configured as OFF, LOW or HIGH
• A low alarm switches on when % O
off when % O
• A high alarm switches on when % O
off when % O
• When the instrument is warming up (cell temperature not stabilized) both
relays are OFF
36
PIN 6 PIN 5
RS485 RS485
B A
PIN 5 PIN 4
Hi Alarm Hi Alarm
NO NC
is above the set point + Hysteresis
2
is below the set point - Hysteresis
2
XTC601 User's Manual
PIN 4 PIN 3
Ch2 Ch2
O/P O/P
- +
PIN 3 PIN 2
Low Alarm Low Alarm
C
is below the set point and switches
2
is above the set point and switches
2
97400 Issue 3.1, January 2017
PIN 2 PIN 1
Ch1 Ch1
O/P O/P
- +
PIN 1
Low Alarm
NO NC