Manuals > Device Connection Guide > Mitsubishi Electric > Private Protocol

Precautions for Use

This connection method uses a private protocol, but is not recommended due to its slow communication speed.

Unless you have a specific reason not to, use the public protocol.

About the connection example

Please see below for an example of connection settings for this driver.

Applicable models etc.

explanation

Connection example [A series]

This is an example of connection settings with the A series via RS-232C (private protocol).

Important Notes

In the following explanation, when we simply say "computer link unit", it also includes the "serial communication unit".

Common to all CPUs

For information on how to set up CPU and various communication units, please refer to the manual for each CPU or unit. When setting the "I/O number", set the value to "1/16" of the first I/O number of the target unit.

If you want to access other stations via a Ethernet unit, please set "MELSECNET/10 routing information" in the Ethernet unit.

In addition, in this case, for "MELSECNET/10 Routing Method", specify a method other than "Automatic response" (IP address calculation method, table conversion method, or combined method).

When setting up a connection via "Computer Link" as "via 1 network":

If you want to access other stations by inserting another computer link unit into the connection station (via the computer link unit) in addition to the computer link unit linked to the PC, select "Computer Link" in "Via 1 Network".

If you want to access other stations using a "multi-drop link" with one computer link unit, select either "Computer link (MD independent)" or "Computer link (MD linked)" (for Q series Q mode/QnA series CPUs) or "Computer link (multi-drop)" (for A series CPUs) in "Via 1 network" ("MD" is an abbreviation for "Multi Drop").

When connecting a Q Series Q mode CPU to a connection station and accessing other stations via a "multi-drop link":

A unit will be in "independent" mode if its parameters are set as follows:

•CH1 side: Transmission setting operation setting = independent (0), communication protocol setting = 0

•CH2 side: Transmission setting operation setting = Independent (0)

Setting the unit parameters as follows will put it into "linked" mode.

•CH1 side: Transmission setting operation setting = independent (0), communication protocol setting = 8

•CH2 side: Transmission setting operation setting = Interlock (1), communication protocol setting = 0

When set to "linked" mode, make sure to set the "sum check (SW06)" in the transmission specification S/W switch settings of the parameter to "Yes (ON)." If it is "No (OFF)," a communication error will occur and communication will not be possible.

When connecting a QnA Series CPU to a connection station and accessing other stations via a "multi-drop link"...

The unit will be in "independent" mode if you set the switches as follows:

•CH1 side: Mode setting switch = 5, operation setting switch SW01 = OFF

The unit will be in "linked" mode if you set the switches as follows:

•CH1 side: Mode setting switch = 0, operation setting switch SW01 = OFF

•CH2 side: Mode setting switch = 5, operation setting switch SW01 = ON

When a Q Series Q mode CPU is connected to the connecting station, the settings of [Transmission speed] and [Flow control] in "Port settings" must match the settings of the serial communication unit of the connecting station.

When a QnA Series CPU is connected to a station, the settings of [Transmission speed], [Parity], and [Flow control] in "Port settings" must match the settings of the serial communications unit of the station.

When an A Series CPU is connected to a node, the [Sum Check] settings in "Port Settings" and "Advanced Settings" must match the settings of the computer link unit of the node.

Q Series Q Mode

When installing an Ethernet unit in the target station to access other stations, set the values specified in the parameter settings of the Ethernet unit to the "Network number of the target station unit" and "Station number of the target station unit".

QnA Series

When installing a Ethernet unit in the target station to access other stations, set the values specified in the Ethernet unit's parameter settings to the "Network number of the target station unit" and "Station number of the target station unit." Regardless of whether you are accessing your own station or other stations, when connecting to a QnA series CPU via an equivalent unit to the "AJ71UC24" or "AJ71C24," use the "A series computer link unit (UC24)" or "A series computer link unit (C24)" settings.

In addition, the QnA Series CPU of the target station operates as an AnACPU.

If you insert a C24 series computer link unit into the connection station, access to other stations via MELSECNET/10 will be via the MELSECNET(II) image, so set the following value to the "Target station unit station number".

If the MELSECNET/10 unit on the connected station side is the control station: Specify the actual station number of the MELSECNET/10 unit on the target station side.

If the connecting station's MELSECNET/10 unit is a normal station: The target station's MELSECNET/10 unit must be the control station, and must be specified as "0" (master station in the MELSECNET(II) image).

When a C24 series computer link unit is inserted and connected to a connecting station, other stations can only access the network specified by the "Units valid when accessing other stations" in the network parameters of the connecting station.

Q Series A Mode/A Series

If the MELSECNET/10 unit on the connected station side is the control station: Specify the actual station number of the MELSECNET/10 unit on the target station side.

(Not recommended) RS-232C A Series

(Not recommended) RS-232C A Series