Watlow CPC400 - Manual (Page 206)

Appendix A: Modbus Protocol CPC400 Series User’s Guide
192 Watlow Anafaze Doc. 0600-2900-2000
Force Multiple Coils 15
Forces each coil (0X reference) in a sequence of coils to ei-
ther on or off. When broadcast, the function forces the same
coil references in all attached slaves.
00 04 00 00
No
Response
Force Listen-Only Mode (04): Forces the addressed slave to
listen-only mode for Modbus communications. This isolates it
from the other devices on the network, allowing them to con-
tinue communicating without interruption from the addressed
slave. No response is returned.
When the slave enters listen-only mode, all active communi-
cation controls are turned off. The ready watchdog timer is
allowed to expire, locking the controls off. While in this mode,
any Modbus messages addressed to the slave or broadcast
are monitored, but the slave does not take any action or send
any responses.
The only function that will be processed after the mode is
entered will be the Restart Communications Option function
(function code 08, subfunction 01).
00 0A 00 00
Echo Query
Data Clear Counters (10): Clears all communication event
counters. Counters are also cleared upon powerup.
00 0B 00 00
Total Mes-
sage Count
Return Bus Message Count (11): Returns the quantity of mes-
sages that the slave has detected on the communications
system since its last restart, clear-counters operation or pow-
erup.
00 0C 00 00
CRC Error
Count
Return Bus Communication Error Count (12): Returns the
quantity of CRC errors encountered by the slave since its last
restart, clear-counters operation or powerup.
00 0D 00 00
Exception
Error Count
Return Bus Exception Error Count (13): Returns the quantity
of Modbus exception responses returned by the slave since
its last restart, clear-counters operation or powerup.
00 0E 00 00
Slave Mes-
sage Count
Return Slave Message Count (14): Returns the quantity of
messages addressed to the slave, or broadcast, that the slave
has processed since its last restart, clear-counters operation
or powerup.
00 0F 00 00
Slave No
Response
Count
Return Slave No-Response Count (15): Returns the quantity
of messages addressed to the slave for which it returned no
response (neither a normal response nor an exception
response) since its last restart, clear-counters operation or
powerup.
Sub-
function
Data Field
Description
Query Response