Rockwell Automation 1738-485ASCM12 ArmorPoint I/O RS-485 ASCII Module, Series A - Manual (Page 10)

Publication 1738-IN010A-EN-E - June 2004
10 ArmorPoint I/O RS-485 ASCII Module, Series A
Specifications Following are specifications for the 1738 ArmorPoint ASCII module.
ArmorPoint 1738-485ASCM12 Module
Inputs per Module
1 full duplex
Input Voltage
Some RS-422 and RS-485 equipment use “+” and
“-” descriptors. The “-” corresponds to “A” and the
“+” corresponds to “B”.
“0”, Asserted, ON, Space, Active
“1”, Disasserted, OFF, Mark, Inactive
Threshold Voltages
Signal A with respect to Signal B
RS-422 RS-485
+2 to +6V dc (Transmitter) +1.5 to +6V dc (Transmitter)
+0.2 to +7V dc (Receiver) +0.2 to +12V dc (Receiver)
-2 to -6V dc (Transmitter)
-1.5 to -6V dc (Transmitter)
-0.2 to -7V dc (Receiver) -0.2 to -7V dc (Receiver)
Indicators 1 green/red module status indicator, logic side
1 green/red network status indicator, logic side
2 green TXD, RXD status indicator, logic side
Keyswitch Position 2 (specialty)
PointBus Current, Maximum 75 mA @ 5V dc
Power Dissipation, Maximum 0.75 W @ 28.8V dc
Thermal Dissipation, Maximum 2.5 BTU/hr. @ 28.8V dc
Isolation Voltage
(continuous-voltage withstand rating)
50V rms
Tested at 1250V ac rms for 60s
External dc Power
Supply Voltage
Voltage Range
Supply Current
24V dc nominal
10-28.8V dc
15 mA @ 24V dc
Fault protected to 28.8V dc
Serial Port Parameters
Serial Character Framing 7N2, 7E1, 7O1, 8N1, 8N2, 8E1, 8O1, 7E2, 7O2
Serial Port Comm Speed 9600, 1200, 2400, 4800, 19.2k, 38.4k
Serial Port Receive from ASCII Device
Maximum Number of Receive Characters 1-128
Receive Record Start Mode No, exclude, include start delimiter
Receive Start Delimiter ASCII character
Receive Record End Mode No, exclude, include start delimiter
Receive End Delimiter ASCII character