Campbell Scientific MD485 RS-485 Multidrop Interface - Manual (Page 65)

Appendix H. MD485 Port Pin
Descriptions
CS I/O Port
The CS I/O port is Campbell Scientific's input/output port. It is not a standard
RS-232 pin-out. The following table provides pin-out information on the port
when connected to a datalogger.
CS I/O CONNECTOR, 9-PIN D-SUB MALE
PIN I/O FUNCTION DESCRIPTION
1 NC 5 V Supplied by
Datalogger
Datalogger sources 5 VDC to
power peripherals
2 GND GND GND
3 O Ring Raised by modem to put
datalogger into
telecommunications mode
4 O RX Serial data receive line
5 I Modem Enable Raised when datalogger
determines that associated modem
raised the ring line
6 I Synchronous Device
Enable
Used by datalogger to address
synchronous devices; can be used
as a printer enable
7 I CLK/Handshake Used by datalogger with SDE and
TX lines to transfer data to
synchronous devices
8 PWR 12 V Supplied by
Datalogger
Datalogger sources 12 VDC to
power peripherals
9 I TX Serial data transmit line
I = Signal Into the MD485, O = Signal Out of the MD485, NC = No
Connection
RS-232 Port
The “RS-232” port is a partial implementation of RS-232C. It is configured as
Data Communications Equipment (DCE) for direct cable connection to Data
Terminal Equipment (DTE) such as a PC serial port.
H-1