Service and troubleshooting
EST3 Installation and Service Manual 8.47
Signature controller modules
Substituting Signature controller modules
When substituting a “known good” Signature controller module
in place of a suspect rail module, you must download the system
configuration and Signature data circuit information into the
CPU module. This operation requires a PC and the SDU
Program.
The Signature controller module actually has two separate
memories. The first memory contains the firmware that makes
the module operate. If there is a problem with the firmware, or if
an upgrade has been issued, the new firmware is downloaded
into the module. When upgrading the module firmware (code),
you do not need to download the “Bootstrap” data unless
specifically instructed to do so.
The SDC configuration information is stored in the module’s
second memory. If you suspect that the module itself is bad, you
must download the configuration information for the circuit that
will be connected to the substitute module.
The database must be converted before it can be downloaded
into the Signature controller.
Table 8-29: Signature controller module troubleshooting
Problem Possible cause
Signature Data Circuit Open 1. Circuit incorrectly wired or connector loose
2. Defective detector or isolator base
3. Broken conductor
4. Device not installed on circuit
5. Device not entered into SDU databases
Signature Data Circuit Shorted 1. Circuit incorrectly wired (often crossed wires on a device
base)
2. Defective detector, detector base, or module
3. Nicked insulation between conductors
Signature Data Circuit Ground
Fault
1. Pinched wire between device and electrical box
2. Nicked wire insulation
Mapping errors
Table 8-30 provides basic information on mapping errors. For
detailed information on identifying and locating mapping errors,
refer to the SSDC Diagnostic and Status sections found later in
this chapter.