Toshiba S20LP instruction manual Message transmission, Computer link protocol, PC link protocol

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7. Message transmission

7.1 Message transmission

The message transmission is text transmission to be performed communication on request. This transmission is following two protocol.

∙Computer link protocol

∙PC link protocol

7.2Computer link protocol

The host machine can communicate to a T2N/T3H on the S20LP using the computer link protocol. Since this function executes the station and firmware, there is no need to create pecial user programs for the T2N/T3H using the slave station.

The host machine used this protocol can execute following process for the T2N/T3H.

∙Upload or download user programs.

∙Status observation (reading out RUN/HALT/ERROR status).

∙Read or write register/device data.

∙Execute control commands.

The computer link protocol cannot execute following process.

∙T2N/T3H is Down mode.

∙A S20LP-station except for ONLINE and STANDBY mode.

7.3PC link protocol

This section presents an overview of the SEND and RECV instructions, which are the instructions that are used to control the S20LP-station from T2N/T3H user programs. S20LP- station transmission control (PC link protocol transmission) is performed solely using the SEND and RECV instructions. See the individual items for details on the actual requests sent to the S20LP.

The PC link protocol allows one T2N/T3H on network to write or read register data to another T2N/T3H.

When this function is used on the PC link slave station, there is no need to create special user programs for the T2N/T3H using the slave station.

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