Stucture ARCNET_DCB
Description:
Describes the settings of the ARCNET controller such as
Declaration:
Members:
Member(s) | Description |
b_node_id | identifies the own node id. The node id of a node must be unique throughout the whole network. Note: By passive initialization (b_init_behaviour=eARC_INIT_PASSIVE) is also possible to use an ID from other node. In this case controller intialized as shadow node. |
z_ckp1 z_ckp2 z_ckp3 |
Busspeed clock divider. That is use to set network speed from 156,25Kbit/s to
2,5Mbit/s.
For SMSC ARCNET controllers corresponds to CKP bits in register SETUP1 |
z_et1 z_et2 z_et3 |
Define the extended timeout. Typical setting for 2.5Mbps are z_et1=1,z_et2=1 and z_et3=0. Note: The extended timeout should be set equal in all nodes of the net. For SMSC ARCNET controllers corresponds to ET1,2 bit in register CONFIG and bit 5 in SETUP1 |
z_fournaks | 20020 and compatibles: If set to 1, the controller tries a maximum of 4 times to send a packet to another node, that responds with NAK (=“no free buffer to receive packet“). Otherwise the controller tries a maximum of 128 times, before the EXCNAK-condition is set. 90C66/90C165 and compatibles: The driver terminates retransmitting because of NAKs from the receiving station by a worst case timeout (appr. 2.4 sec. if z_fournaks is set, otherwise appr. 2 min !) |
b_init_behaviour | Define the controllers behaviour in case of if no token is seen or no activity is detected.
|
z_p1mode z_backplane |
Must be set accordingly to the used interface:
For SMSC ARCNET controllers corresponds to P1MODE bit in register SETUP1 and BACKPLANE bit in CONFIG register |
For more information on the above mentioned settings, refer to the ARCNET-controllers datasheets, that are available from SMSC (www.smsc.com).
Notes:
1) It is strongly not recommended to use ET3 setting as it behaviour was not specified by SMSC.
2) Be aware about consequencies of the forced intialization (b_init_behaviour=eARC_INIT_FORCED). If speed settings of the
controller do not match the speed of the network, then controller will fail to detect a token and will repeatedly generate
reconfiguration bursts. These permanent reconfiguration bursts will block data transfer in whole network
Requirements:
passive initialization mode (b_init_behaviour=eARC_INIT_PASSIVE) is supported only since SH ARC-USB driver v4.4.
See also:
DeviceIoControl()
ARCNET_EXTND
IOCTL_FARC_INIT
IOCTL_FARC_EXTND_FUNCTIONS
IOCTL_FARC_GET_USEDDCB
IOCTL_FARC_ARC_TRANSMITTER_CTRL