－2－
1
GENERAL
Three types of communication interfaces (RS-232C, RS-422A and RS-485) are available in the SE3000
series field scanner, and receiving of measured data and settings of various parameters can be executed
by a personal computer (PC).
1.1 RS-232C Communications Interface
The RS-232C is the data communications standard being set and issued by EIA (Electronic Industries
Association) in the USA and JIS C 6361 in Japan.
This standard is a basic interface between MODEM and connected data terminal units, and specifies
electrical and mechanical specifications only. Most of the RS-232C communications interface is being used
for personal computers and industrial instruments such as the SE3000 series field scanner do not
completely conform to this standard at present, and have different signal wire numbers, connectors to those
specified in the standard. Also, since this standard does not specify any software parts, or so-called [data
transmission procedures], units having the RS-232C communications interface can not be interconnected
with each other unconditionally. With these reasons, users must survey and check the specifications and
transmission procedures in advance of units being connected. However, if the counter unit is a personal
computer or a similar device that can optionally program the specifications, all the units can be combined by
having proper programs prepared by a program designer.
1.2 RS-422A/485 Communications Interface
The RS-422A and RS-485 communications interface can communicate with multiple SE3000 series field
scanners (up to 31 sets) in parallel by signals conforming to RS-422A and RS-485.
There are few personal computers that provide RS-422A or RS-485 communications interface. However,
since these communications interfaces are characterized with serial communications, these are easily
connectable to the personal computer having the RS-232C communications interface by using an RS-422A
or RS-485
⇔
RS-232C signal converting unit. A line converter (Model SC8-10: sold separately) is available
for RS-422A and RS-485
⇔
RS-232C signal conversion at CHINO.
For the difference between RS-422A and RS-485 communications interfaces, the RS-422A needs four
signal cables, while RS-485 needs only two signal cables.
2
COMMUNICATIONS PARAMETERS
The communications parameters of the SE3000 series field scanner are as follows. The parameters
marked with * are defaults.
* Half-duplex (polling selecting system)
* Protocol: MODBUS protocol (
*
RTU mode / ASCII mode )
* Transmission speed: 19200,
*
9600 bps selectable
* Start bit: 1 bit
* Data length: 7 bits /
*
8 bits selectable (depending on transmission mode)
* Parity bit: Even / Odd /
*
Disabled selectable (depending on transmission mode)
* Stop bit:
*
1 bit / 2 bits selectable (depending on transmission mode)
* Transmission code :
*
Binary / ASCII (depending on transmission mode)
* Error check:
*
CRC-16 / LRC (depending on transmission mode)
* External units given priority for communications
* Data transmission procedure: None
* Signals in use: Transmitted and received data only (no control signal in use)
The change of the communications parameters is executed by the “parameter programming software
package (PASS – Separate purchase is required.)”.
Caution
